Real progress toward large-scale comprehensive service delivery to children and their families is possible only when community agencies move beyond cooperation to genuinely collaborative ventures at both the service delivery and system level. The following factors that affect the success of collaborative efforts were developed from an analysis of 13 interagency initiatives that include the cooperation of a school with at least one human services agency: (1) the climate in which initiatives begin; (2) the processes used to build trust and handle conflict; (3) the people involved; (4) the policies that support or inhibit their efforts; and (5) the ongoing availability of resources. The following guidelines for new partners are outlined: (1) involve all key players; (2) choose a realistic strategy; (3) establish a shared vision; (4) agree to disagree in the process; (5) make promises you can keep; (6) focus on common goals; (7) build ownership at all levels; (8) avoid convenient excuses that prevent partners from working together; (9) institutionalize change; and (10) publicize success. An inventory of questions to help agencies assess the need for interagency partnerships is included. Thirteen program descriptions, a list of resource organizations, and a 56-item bibliography are appended. (FMW)