This guide to the Latch Key program for after-school day care explores rationale and methods for developing Latch Key programs in the public schools to provide low cost after-school care for children (grades 1-6) of working or student parents. (Some programs have been provided for kindergarten children and some have been expanded to full time during summer and holiday periods.) The booklet outlines Latch Key program goals and the community education concept of maximum use of tax-supported schools to meet the needs of all age groups in the community. Community support factors are cited and support and financing strategies described. A section on leadership, staffing and training covers the coordinator's role, use of public school and paraprofessional personnel, and inservice training. A section on parent participation deals with the crucial role of parent advisory groups and the need for informal parent involvement. Discussion of program operation considers relationships with regular school personnel, state licensing regulations, personnel standards and program evaluation. (BF)