This guide explores the key issues in the development, sustainability, and effectiveness of after-school programs including before school, weekends, and summers, and identifies federal strategies to promote effective programs. The first part of the booklet presents the core elements of an effective after-school program, noting that programs should: (1) be based on research on early adolescent development; (2) emphasize social relationships by encouraging a family-like atmosphere; (3) encourage parental involvement; (4) be developed for and by youth and tailored to specific community and neighborhood needs; (5) be flexible, fun, culturally relevant, and linked to activities that capture adolescents' interests; (6) provide food; (7) have clear rules for membership; (8) collaborate with local community organizations; (9) be safe and accessible to all youth; (10) provide linkages to schools; and (11) offer a wide array of services. The second part proposes federal strategies to promote after-school programs, suggesting that the federal government can provide leadership in supporting such programs for young adolescents through supportive legislative and innovative funding mechanisms. The appendixes provide an overview of selected federally-supported after-school programs and a list of organizations that are useful resources for youth professionals expanding their programs during the out-of-school hours. (AA)