Energy Efficiency and Renewable Energy Website (http://www.eere.energy.gov)
U.S. Department of Energy website with extensive links to publications, other websites.

Home Energy Saver (http://www.homeenergysaver.lbl.gov/)
Interactive government website that allows you to specify a residence, then calculates energy and financial performance of energy design elements that you specify.

NC Solar Center (http://www.ncsc.ncsu.edu/)
The NC Solar Center has information and factsheets on many issues related to solar energy in N.C. – including the N.C. Renewable Energy Tax Credits.

NC Sustainable Energy Association (http://energync.org/)
This is a renewable energy membership organization that has both practical and policy information about renewable energy technologies in North Carolina.

Energy Star (http://www.energystar.gov/)
A federal government website that describes energy-efficient products and maintains lists of "energy star"-rated products.

Oak Ridge National Lab Building Technology Center (http://www.ornl.gov/btc/)
This is a building technology site with publications/factsheets, links.

Southface Energy Institute (http://www.southface.org/)
Nonprofit organization that has factsheets on many issues related to residential energy efficiency and building science.