Wholenote.com is pretty good for basic theory but you gotta watch out regarding where you're getting your info. Anyone can post lessons over there from true experts with music school credentials to little kids without a clue. Look for lessons by Chris Sung, J. Cotton, Fred Burton, these are all good guys with a lot of knowledge.

I might also suggest my modest site -- but the theory leans in the direction of people who already have a lot of theory under their belts are and looking for ways to mix things up a bit or break out of obligatory ways of thinking
http://guitarsoc.homestead.com

bofa