This training guide was developed by the United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP) to support the efforts of government, civil society institutions and youth work personnel, engaged in training young people on development issues. It is intended to provide insight into the peer-to-peer approach to life skills training in non-formal education settings in the Asian and Pacific region. This publication is designed as a tool for strengthening training knowledge and skills of peer educators working with youth on the prevention of HIV and AIDS and substance use. This guide is composed of 11 modules with an annex on training needs assessment; with each module designed to stand alone. Pictures, games, exercises, lectures, case studies, general reading and diagrams have also been included to foster participatory learning and action. Inherent in the design is flexibility for innovation and adaptation to suit local contexts.