I'm finding that I'm making fewer mistakes in poker since I started using this site. It offers a whole selection of games to practice with -- some of them I don't really understand why they're needed, but they're fun anyways. Other games I see the real need for, like the one to pick the nut hand quickly.
There aren't so many articles about poker yet, but they seem to be heading that direction. Once the beta is done I suppose they'll have more.