To aid elementary, middle, junior high, and high schools in planning an Instructional Materials Center, this handbook presents standards for this modern concept of a school library. The term Instructional Materials Center (IMC) is used throughout to designate a centralized collection of materials, with a staff of professional and clerical personnel, which provides media services to students, teachers, administrators, and the community. The handbook includes guidelines for the selection, acquisition, and organization of materials; information on the processing of materials; the philosophy behind making materials accessible to students, staff, administration, and community; the minimum standards for audiovisual equipment; the staffing requirements of an IMC; and the funding levels necessary to maintain and up-date materials in an IMC. A bibliography and a directory of publishers are included. (KC)