Sustainable forestry, in its simplest form, is defined as a forest managed so that it is capable of regenerating itself. In other words, harvested trees are replaced by seedlings that eventually grow into mature trees, whose life cycle ranges from one to over thirty years (see figure below). Deforestation and degradation, the two most pressing problems facing the forest sector in many countries today, result from a lack of healthy forest regeneration. In order to efficiently manage forests, policy makers and operational staff require extensive and timely data on tree species, tree cover, forest area, stock, soil, water, climate, and on the inhabitants, flora and fauna dependent on forests for their growth and livelihoods. Recent advances in information and communication technology (ICT) in both hardware and software and declining costs of internet connectivity and connecting devices (phones, computers) have made the collection, verification, analysis, storage, security, and dissemination of large amounts of data and information available to anyone, anytime, anywhere at affordable prices. However, while ICT advances are significant and promising for sustainable forest management, many countries have yet to make use of this opportunity and use information technology to their full potential. This E-book compiles ICT tools and applications relevant to three primary challenges in the forest sector: data used for decision making purposes, governance and institutions, and the empowerment of forest communities. This E-book is a live document which will be updated as frequently as possible and as needed. It has been produced with funding from the Program for Forests (PROFOR).We welcome suggestions and any initiatives in the use of ICT tools and applications for sustainable forest development which you may be aware of for inclusion in this E-book.