This document discusses principles and methods for developing managers. It outlines that manager development is a threefold responsibility to the enterprise, society, and individual. It emphasizes developing managers for the tasks of tomorrow rather than yesterday through challenging opportunities for growth. Key principles include developing the entire management group dynamically and focusing on performance over promise. Methods discussed include on-the-job training through coaching, mentoring, job rotation, and instruction as well as off-the-job training using sensitivity training, transactional analysis, lectures, and simulations.