This sourcebook contains ASSIST training materials designed to prepare paraprofessionals for their role as teacher aides in classes for handicapped preschool children. The preservice portion of the training program focuses on the special relationships the instructional associate has with the teacher, the preschool, and the child. Chapter I presents information on the responsibilities of instructional associates, with discussion of the role of the teacher aide, relations to other staff, relationships with parents and community, and regulations and procedures. Chapter II presents an overview to preschool programs, including sections on the importance of preschool, advocates for handicapped children, the newly acquired legal rights of handicapped children, different types of preschool programs, different preschool philosophies, and issues related to serving handicapped children. Chapter III looks at developmental skills and how handicaps affect development. The inservice portion of the training program is divided into six instructional units. The first unit on the instructional process sets the foundation for the remaining units. The other five units focus on the major developmental skill areas: motor, language, social, personal autonomy, and pre-academic. Each unit presents basic facts of child development, information on common handicapping conditions that influence the rate of individual growth, and examples of application of the instructional process within its skill area. Self-checking exercises for the paraprofessional are also included in each unit. (JMB)