This manual is designed to help state and regional water supply training personnel conduct seminars for instructors of water plant operators. The purpose is to help state supervisors upgrade the quality of training given to the plant operators by their instructors. Since a survey indicated that operator training instructors are technically competent, the focus is on training rather than content or operating skills. Section I outlines the procedures involved in planning a seminar for operator training instructors, describes the task of an instructor, and provides an overview of the seminar, forms and questionnaires, and agendas. Section II contains 13 complete lesson plans, each of which has three parts, lesson plan cover sheets, and instructional material. Eight of the lessons address the development and preparation of a good training program including content, objectives, methods, and preparing lesson plans. Five lessons focus on classroom delivery techniques such as group discussion and demonstration. (DC)