This booklet is designed to assist teachers in their use of overhead projectors when teaching geography. With the overhead technique, relationships among patterns can be suggested bit by bit on inexpensive, easily prepared overlays that are projected to sizes appropriate for a particular instructional situation. A general discussion of the features of overhead methodology includes the anatomy of the overhead projector, overhead transparencies, and techniques of overhead presentation. The preparation of overhead transparencies is described, using original drawings, one-to-one copies, and photographs. The use of slides is also described. An overhead projector has many roles, such as replacement for other types of projectors, chalkboard substitute, substitute for wall maps and charts, superimposition, and dual screen. Teachers can experiment or use the 17 transparency masters that conclude the booklet. Guidelines are included for using the masters, which represent simple and complex progressive disclosure, simple additive-subtractive cells, production techniques, and reproduction techniques. (ND)