Teachers, librarians, and other school personnel are often unaware of the variety of free teaching materials available: government agencies, national associations, and manufacturers produce many specialized items designed not only to complement instructional materials regularly available through the schools, but also to provide assistance in the teaching of specialized matter. This fourth edition of a resource guide to such free materials is organized by curriculum topics such as agriculture, art, business, conservation education, English and language arts, health education, home economics, industrial education, mathematics, music, occupational guidance, physical education, safety and driver education, science, social science, and teacher aids. Items are listed by producer-source, and information is given about other materials available from that source, availability of the item, grade-interest level of the material, and a brief content description. An index and appendix of film services are also included. (Author/SH)