You can also look at www.amdmb.com. Forums discussing the various AMD motherboards and other assorted hardware issues. Many good links and an excellent troubleshooting guide.
www.icrontic.com www.sharkyforums.com www.beyond3d.com
firingsquad.gamers.com [not for the forum though]
I'm oriented towards 3D graphics in my own interest. There are a few more forums but not all of them are so good.
www.arstechnica.com computer nerds galore, not that that's bad They can really answer all your questions and you'll usually get several replies within the same day. tip: remember the search function.
AnandTech is good - if you can get on it. They have a bandwidth cap in place at the moment which makes the site run... well, very slowly. Also, the large number of new posts means your question will be out of view very quickly.