The data on which the advice is based came from a literature review, discussions with experts, and a telephone survey of law enforcement specialists in the 50 Law Enforcement Assistance Administration (LEAA) State Planning Agencies. Information also came from a telephone survey of over 200 police agencies taking part in support service sharing arrangements, discussions with an advisory panel, and site visits to 4 successful cooperative systems. An introductory chapter explains the purposes and methods of sharing communications. Subsequent chapters explain how to install a cooperative system. They cover planning, organizing, managing personnel resources, managing financial resources, and operating a service sharing arrangement. The evaluation of a sharing arrangement and other support services which are appropriate for sharing are also discussed. Tables, figures, and footnotes are provided. Appendixes present sources of further information, sample forms and contracts, and related materials.