Describes the methodology for developing computer textbooks and training systems. The main attention is paid to the conceptual design stage, at which the appearance of the product is formed, its content is determined, the main functions and most important characteristics are specified, fundamental didactic and software and hardware solutions are developed. The classification of computer training tools, principles and methods of structuring educational material, models describing the order of navigation through its structural units, methods of computer didactics, methods and algorithms for knowledge control, methods for choosing development tools are considered. Models and methods for generating training tasks are proposed. The book is designed for current and potential creators of computer training tools (scientists, teachers, methodologists, information technology specialists), software developers, organizers of the educational process, senior students and graduate students.