This paperback course textbook has been adapted from the landmark four-volume Handbook of Applied Developmental Science (SAGE 2003), a work that offers a detailed roadmap for action and research in ensuring positive child, youth, and family development. In 20 chapters, this new single-volume work brings together the latest in theory and application from applied developmental science and the positive psychology movement for students going on to careers working with youth and their families in educational and community environments.