I am going to be fairly selective in recommending useful sites. Please see below for signficant sites on household energy. If you have any sites you think should be included, send me an email and I will review them.
ESMAP Specializes in international energy and development policy with emphasis on alleviating poverty. Many useful publications are on this site.
Bioenergy conversion factors; This site gives energy conversion factors for a wide variety of biomass fuels. (Oakridge National Laboratories)
Power and Energy Conversion Factors. This site provides all types of power conversion factors in interactive way. (Unitconversion.org)
Africa Electricity Initiative. This is a relatively new site that is to promote an exchange of information about both grid and offgrid rural electrification in Sub-Saharan Africa.
Global Alliance for Clean Cookstoves. This is a relatively of new major effort to raise awareness of household air pollution and to promote over 100 million stoves over the next 10 years.
HEDON or the Household Energy Network is a major international forum for knowledge exchange on household energy. It also has a flagship publication known as Boiling Point.
Energia: Energy and Sustainable Development Premier network on gender and energy
Partnership for Clean Indoor Air Unique international partnership for alleviating indoor air pollution in developing countries.
Kirk Smith's Site on Global Environmental Health UC Berkeley Leading site on scientific inquiry into indoor air pollution issues with many interesting publications.
WHO Website for Indoor Air Pollution WHO has been the lead international organization to recognize health problems of indoor air pollution in developing countries.
UNDP Energy for Sustainable Development has a wealth of documentation on energy and the poor.