Gosh I wish I'd found this thread earlier. It's like a whole list of great and active self-improvement sites in one spot.
Here's a couple of my own posts that might be of interest for being Stumbled, while I check out many of the links here I hadn't come across before.
Self Help Blog › The Quicksand Guide To Professional Help - I'm looking for contributions :-)
Self Help Blog › “Law of Attraction” Is Good? - short, but my opinion
Keep up the great articles and blog posts everyone!