One thing I did find very useful with deviantArt is just looking at what other artists are doing. ConceptArt.org was the premiere art forum for technique, but most of the art was focused on industry level conceptual design, which is not what I wanted to head towards. DeviantArt has a LOT of really good anime/anime influenced artists. There's a lot of stuff I've picked up just by studying some of the techniques they use.
That and marketing yourself. That's not something they teach, but I've learned quite a bit just by observing what other popular artists are doing or did to become popular.