Roofing
National Roofing Contractors Association – http://www.nrca.net
Midwestern Roofing Contractors Association – http://www.mrca.org
Renewable Energy
Texas Renewable Energy Industries Association – http://www.treia.org
National Renewable Energy Lab – http://www.nrel.gov
Database of State Incentives for Renewables & Efficiency – http://www.dsireusa.org
North American Board of Certified Energy Practitioners – http://www.nabcep.org