The information systems/centers listed in this guide are organized into the following five sections according to their area of concentration: (1) Education/Special Education; (2) the Sciences; (3) Physical Education, Recreation, and Related Areas; (4) Products and Services for Handicapped Consumers; and (5) Other. The systems and centers have also been listed alphabetically in a chart which appears at the beginning of the guide. This chart gives a general overview of each system, including main subject area, type(s) of materials available through the system (professional-use, child-use, or consumer-use), and the general services provided. The chart also serves as a table of contents. Terms used in describing the systems and centers are defined at the end of the guide, and suggestions for locating additional information are presented. (BD)