Based on experience gained in a project in Vermont that is demonstrating potential applications of telephone conferencing to services for the developmentally disabled, this paper summarizes the most important factors in establishing a telephone conferencing system. Basic terminology is described and factors to be considered in selecting telephone instruments are discussed. Some simple guidelines are provided on how to deal effectively with telehone companies and some general statements are made about costs of various services. The importance of good training for users is also discussed. The appendices include descriptions of eight kinds of end instruments that were tested for the Vermont project and a list of eight publications on telecommunications and service to the developmentally disabled. (CHC)