Solstice Just about everything you wanted to know about energy efficiency and renewable energy.
Home Power Magazine Small-scale solar and other renewable energy design.
Cities for Climate Protection Campaign These cities will be trying to improve energy efficiency and reduce fossil fuel use.
American Wind Energy Association The trade organization of the U.S. wind energy industry.
Rocky Mountain Institute The absolute best place to get information on sustainable energy.
Swedish Environmental Institute A fair amount of emphasis is on Africa, but lots of info that applies everywhere.
EnviroVideo produces videos on nuclear power, nukes in space and many other environmental issues.