PROFOR is a multi-donor partnership to enhance forests' contribution to poverty reduction, sustainable development and protection of environmental services.
The World Bank's poverty research website , which has a number of useful documents and tools (and after typing their web-address everything becomes easy on this page).
FAO's forestry page , the main source for key statistics on forestry at national levels. More limited on local studies of poverty and forests, an exception is FAO Forestry Paper 149: "Better forestry, less poverty. A practitioner's guide", found at: http://www.fao.org/docrep/009/a0645e/a0645e00.htm
The CGIAR Systemwide Program on Collective Action and Property Rights (CAPRi) has several links and papers relevant for forest-poverty research, particularly related to local/community forest management.
The Rights and Resources Initiative is a global coalition to advance forest tenure, policy and market reforms.
Forest Trends is an international NGO which has particularly worked on how markets can expand the benefits from forests.