Book excerpt: This book is a comprehensive overview of the forest bioenergy, from feedstock production to end products. The book presents the state of the art of forest biomass production, assessment, characterization, and conversion into heat and power. It starts with forest sources of biomass and potential availability. Continues with the characterization of the forest stands and the availability of biomass for energy per stand structure, including stands managed for timber, non-wood products, and energy plantations. It follows with biomass evaluation and monitoring considering data sources, modeling methods, and existing models. are also addressed. After the initial focus on forest biomass production and estimation, this resource is assessed as a feedstock for energy conversion. Not only current, but also emerging biofuels obtained from forest biomass are considered. Established and emerging conversion technologies for the production of bio-heat and bio-power are examined and the impacts of the conversion systems presented.