Noting that many communities in the United States have set the ambitious goal of enhancing school readiness, this report is intended to help communities invest wisely in school readiness initiatives. Part 1 of the report summarizes recommendations from the National Education Goals Panel (NEGP) for defining and assessing school readiness. The core conclusions are that: (1) school readiness is multifaceted; (2) family and community supports for readiness are essential to address in an assessment of readiness; and (3) school readiness is a reciprocal phenomenon. Key principles for appropriate assessment of young children are also summarized. Part 2 presents a framework for community investments based on an ecological view of child development. This framework is broader than that of the NEGP and considers factors related to the child's physical and mental health, the family context, children's experience of early childhood care and education settings, and the neighborhood context. A selective review of research is presented, emphasizing rigorously implemented experimental evaluations of intervention, longitudinal studies, and studies using multivariate analyses. Part 3 of the report delineates implications for community action and summarizes the most effective investments for school readiness, based on the review of research. Presented in tabular form, the summary identifies the level at which intervention might occur, starting at the level of the child and working outward to community-level factors and beyond. Interventions with significant impacts on school readiness are summarized, with information on interventions shown to be ineffective, as well as interventions with mixed results. Interventions that are theoretically important but without empirical evidence of their effectiveness are also summarized. The areas of intervention are: (1) child health (immunizations, nutrition, unintentional injury, lead exposure, dental health, emotional and behavioral problems); (2) family factors (economic risk, family structure, home environment); (3) early childhood care and education; (4) school transitional practices; (5) emergent literacy; (6) community/neighborhood factors; and (7) media effects. (Contains 256 references.) (KB)