School Readiness Act of 2003 - Amends the Head Start Act (the Act) to revise and reauthorize Head Start programs. Title I: Head Start Reauthorization and Program Improvements - (Sec. 103) Extends through FY 2008 the authorization of appropriations for Head Start programs, with specified amounts for impact studies, other research, demonstration, and evaluation activities, and administrative expenses. (Sec. 104) Revises requirements for allotment of and limitations on use of Head Start funds. Sets at one percent of appropriations the amount the Secretary of Health and Human Services (the Secretary) is required to reserve for training and technical assistance activities, and distribute in the following portions: (1) at least 50 percent to local Head Start agencies for certain uses and for complying with specified quality standards; (2) at least 30 percent to support a State system of early childhood education training and technical assistance; and (3) at least 20 percent for the Secretary to assist local programs in meeting certain quality standards. Reserves another one percent to be used by the Secretary to fund other activities, with the following portions to be made available: (1) at least 25 percent for expansion of services by Migrant and Seasonal Head Start programs (or, if numbers of migrant and seasonal eligible children are insufficient, for other disadvantaged populations,); and (2) at least 60 percent for specified quality improvement activities. Requires that a portion of any remaining funds (after specified reservations) be made available to expand services to underserved children such as those under the Early Head Start and Migrant and Seasonal Head Start programs. Revises activities for which quality improvement funds are to be used to include outreach to homeless families, migrant and seasonal farmworker families, and families with children with a limited English proficiency. Changes from discretionary to mandatory the authority of the Secretary to award grants to assist collaboration among State early childhood education activities under Head Start and other activities carried out in and by the State to benefit low-income children and families, and by Head Start agencies with other State and local planning, resource, and referral agencies. Requires appointment of a State Director of Collaboration (currently State liaison), and establishment of an Office of such State Director. Requires coordination among various entities for strategic planning for outreach to eligible children and implementation strategies. Requires a needs assessment to: (1) include assessing availability of high-quality prekindergarten services for low-income children; and (2) be updated annually and made available to the general public in the State. Directs the Secretary to use at least ten percent of specified reserved funds for Early Head Start programs (for families with infants and toddlers). Includes models that leverage existing capacities and capabilities of the delivery system of early childhood education and child care among locally designed or specialized service delivery models for Head Start programs. Requires the Secretary, in allotting funds for expansion of Head Start programs, to consider the extent that an applicant: (1) has involved providers of family support services and protective services for children and families in community-wide strategic planning and needs assessments (among other entities); and (2) plans to coordinate its services with a community liaison designated under the McKinney-Vento Homeless Education Assistance Improvements Act of 2001 (homeless education liaison), as well as (under current law) with the education services of the local educational agency (LEA). Directs the Secretary to require Head Start agencies to: (1) implement policies and procedures to ensure that eligible homeless children are identified and prioritized for enrollment; (2) allow homeless families to apply to, enroll in, and attend Head Start programs while required documents, such as proof of residency, immunization and other medical records, birth certificates and other documents, are obtained within a reasonable time frame; and (3) coordinate individual Head Start centers and programs with efforts to implement homeless children education programs under the McKinney-Vento Homeless Assistance Act. Declares that nothing in the Act shall be construed to require a State to: (1) establish a program of early education for children; (2) require any child to participate in a program of early education; (3) attend school; or (4) participate in any initial screening prior to participation in such program, except under the Individuals with Disabilities Education Act. Requires all curricula and instructional materials funded under the Act to be: (1) scientifically based and age appropriate; and (2) available for parental inspection, upon request. (Sec. 105) Includes community-based or faith-based organizations among the entities that may be designated as Head Start agencies. Requires Head Start grantees to establish and demonstrate they have met their goals for: (1) educational instruction in prereading, premathematical, and language skills; and (2) provision of health, educational, nutritional, social, and other services. (Sec. 106) Revises the additional educational performance standards included as program quality standards, and performance measures for program monitoring. (Sec. 107) Requires Head Start agencies to: (1) comply with quality standards, especially certain educational standards for school readiness; (2) demonstrate capacity to serve eligible children with scientifically-based curricula and other interventions that help ensure the school readiness; (3) conduct outreach to various local entities to generate support and leverage resources of the entire community; and (4) coordinate with the LEA or other agency responsible for the operation of a public prekindergarten program in a community, including outreach to identify eligible children. (Sec. 108) Revises requirements relating to Head Start transition to provide for alignment with K-12 education. Requires Head Start agencies to: (1) include homeless education liaisons among the counterparts in schools with whom they establish communication channels for their own staff; (2) include family outreach and support efforts by homeless children education programs among those with which they cooperate in their own such efforts; (3) develop continuity of developmentally appropriate curricula between Head Start and LEAs; (4) teach parents the importance of their involvement in their child's academic success and strategies for maintaining that involvement as their child moves from Head Start to elementary school; and (5) develop and implement a system to increase program participation of underserved populations of eligible children. (Sec. 109) Requires Head Start agencies, in requesting permission to use Head Start funds to purchase a program facility, to describe: (1) their consultation with community providers demonstrating capacity and capability to provide services under the Act; and (2) the potential for and cost effectiveness of collaboration with such providers as opposed to the cost effectiveness of purchasing a new facility. (Sec. 110) Limits to ten percent of total enrollment the permissible participation of children in the area served who would benefit from Head Start programs, including children referred by child welfare agencies, but whose families do not meet prescribed low-income criteria. (Currently allows participation of such children "to a reasonable extent.") Exempts a military housing allowance from being counted as family income in determining a child's eligibility to enroll in a Head Start program. (Sec. 111) Revises requirements for Early Head Start programs for families with infants and toddlers to include specifically: (1) training in parenting skills and in basic child development; (2) coordination with home-based services; (3) formal linkage with the agency responsible for administering certain provisions of the Child Abuse Prevention and Treatment Act; (4) as eligible providers, migrant and seasonal Head Start programs and community- and faith-based organizations; and (5) professional development to increase program participation for underserved populations of eligible children. (Sec. 112) Revises requirements for technical assistance and training. Directs the Secretary to make available to each State certain reserved funds to support a State-based system delivering training and technical assistance that improves the capacity of Head Start programs to deliver services in accordance with the specified standards. Directs the Secretary to: (1) ensure eligible entities for such systems are chosen by the Secretary through a competitive bid process; (2) ensure that certain existing agencies with demonstrated expertise are included in planning and coordination of such systems; and (3) encourage States to supplement Head Start funds for such systems with other State, Federal, or local funds to expand activities beyond Head Start agencies to include other providers of other early childhood services. Revises requirements for allocating resources for technical assistance and training to include: (1) supplemental amounts for staff training in screening reading assessments (as described in the Early Reading First program under the Elementary and Secondary Education Act of 1965); (2) the needs of homeless children and their families with respect to community-wide strategic planning and needs assessments; and (3) assistance in increasing program participation of eligible homeless children. Includes community- and faith-based organizations among entities eligible for grants to train Head Start personnel in using performing and visual arts and interactive electronic media programs to enhance children's learning experiences. Revises requirements for supporting an organization that administers a centralized child development and national assessment program leading to recognized credentials. Includes among such requirements training for personnel providing services to children who are: (1) abused or neglected; or (2) referred by or receiving child welfare services. Directs the Secretary to provide funds to train Head Start personnel in addressing the unique needs of migrant and seasonal working families, families with a limited English proficiency, and homeless families. Requires the majority of funds expended for such purposes to be used to provide classroom-focused training and technical assistance, and for activities related to: (1) education and early childhood development; (2) child health, nutrition, and safety; (3) family and community partnerships; or (4) other areas affecting the quality or effectiveness of Head Start programs. (Sec. 113) Revises requirements for Head Start Staff qualifications and development. Directs the Secretary to ensure that at least 50 percent of all Head Start teachers nationwide in center-based programs, by September 30th, 2008, have a baccalaureate or advanced degree: (1) in early childhood education; or (2) in a field related to early childhood education, with experience in teaching preschool children. Requires all new Head Start teachers to have at least an associate degree or be enrolled in a program working towards that degree within three years of enactment of this Act. Requires Head Start teachers who have received financial assistance under the Act to teach in a Head Start Center for an amount of time equal to the time period in which they received financial assistance. Directs every Head Start agency and program to create professional development plans for all full-time employees who provide direct services to children. (Sec. 114) Revises research, demonstration, and evaluation activities with respect to the needs of abused or neglected children. Repeals the mandate for a study comparing the educational achievement, social adaptation, and health status of children participating in Head Start programs with that of eligible children who do not participate. Directs the Secretary to use certain funds to contract with the National Academy of Sciences for the Board on Children, Youth, and Families of the National Research Council to establish an independent panel of experts to review and synthesize research, theory, and applications in the social, behavioral, and biological sciences. Requires the panel to make recommendations on early childhood pedagogy with regard to: (1) age and developmentally appropriate Head Start academic requirements and outcomes; (2) differences in type, length, mix, and intensity of services to ensure that children from challenging family and social backgrounds enter kindergarten ready to succeed (including low-income children, children of color, children with special needs, and children with limited English proficiency); and (3) appropriate assessments of young children to improve instruction, services, and program quality, including systematic observation in a child's natural environment, parent and provider interviews, accommodations for children with disabilities, and appropriate assessments for children with special needs, including English language learners. (Sec. 115) Includes homeless children among those Head Start participants whose status the Secretary reports on biennially. (Sec. 116) Revises nondiscrimination requirements to allow religious organizations that receive Head Start funds to take religion into consideration when making hiring decisions for work connected with such organizations' carrying on their activities. Title II: State Demonstration Program - (Sec. 201) Allows up to eight qualifying States to participate in State demonstration programs in which their allocation of Federal Head Start funding would be administered by them through grants to coordinate Head Start with State early education programs. (Current law provides direct Federal funds to local grantees.) Requires a State, in order to qualify, to have: (1) an existing State-supported system of public-pre-kindergarten; (2) implemented standards (as of FY 2003) for school readiness that are aligned with State kindergarten through 12th grade; (3) prior year State and local spending at a level of at least 50% of the Federal Head Start funds to be allocated to the State; (4) an established means for interagency coordination and collaboration; and (5) standards that generally meet or exceed the standards that ensure the quality and effectiveness of programs operated by Head Start agencies. Requires the participating State to continue to give funds to any current local grantee for 60 months after the effective date of the demonstration program (which itself is in effect for five Federal fiscal years), if the local grantee: (1) has no uncorrected deficiencies identified in monitoring reports from the most recent five-year period; and (2) is determined, by the State, to be in compliance with the State's plan for the demonstration program. Provides for Federal allocation of participating State allotments for the basic program, expansion, quality improvement, and training and technical assistance. Sets the Federal share at 95 percent. Authorizes participating States to combine funds for operations with other early childhood education programs serving children in the same age group, if all applicable requirements of the Act are met with respect to either the entire combined program or each child served in such combined program for whom the services provided are funded under the Act. Allows a State to use demonstration program funds for any purpose of the Act, without regard to the specified allotment purposes. Requires the State demonstration program to be coordinated with the education programs of LEAs to ensure that the program is effectively designed to develop in children the knowledge and behaviors necessary to transition successfully to kindergarten and to succeed in school. Requires such coordination with: (1) the Early Reading First, Even Start, and other preschool programs under title I of ESEA; (2) State prekindergarten programs; and (3) the Ready-to-Learn Television program under title II of ESEA. Allows such coordination also to occur with: (1) programs under the Child Care and Development Block Grant Act; and (2) other publicly-funded early childhood education programs. Sets forth requirements for: (1) parental choice; (2) services including child development and education, parent education and involvement, social and family support, and Head Start; (3) State plans, including teacher qualifications, quality standards, and accountability; and (4) Federal oversight, corrective action, and withdrawal of approval. Directs the Secretary to: (1) award a contract for an independent evaluation of such State demonstration program; and (2) submit to specified congressional committees an interim report by October 1, 2006, and a final report by October 1, 2007. Requires any State selected to participate in such demonstration program to: (1) maintain or increase its FY 2003 State funding levels for early childhood education; (2) provide an additional contribution of non-Federal funds, equal to five percent of its Federal Head Start allotment; (3) use Head Start funds only for specified Head Start purposes; (4) provide all comprehensive social services, including health and nutrition, currently available to Head Start children; (5) develop a parental involvement strategy; (6) demonstrate that its qualifications and credentials for early childhood teachers reflect the new requirements established under title I of this Act for for Head Start programs administered by the Federal government; (7) enforce quality standards for Head Start programs that are aligned with K-12 educational standards and that generally standards meet or exceed Federal Head Start performance standards; and (8) continue to provide services that are at least as extensive, and to at least as many low-income children and families, as their FY 2003 levels.