Chess.com is where I play under the name Pegrin. There are so many chess sites out there, but this one has the combination of interface and features that I like best.
ChessTempo is where I practice tactics under the name newlook. It has both a standard (i.e., no time limit) mode and a rating system. It has many other cool features, with new ones added often.
Some chess players upload instructional videos to YouTube. jrobichess and kingscrusher are worth a look.
ChessVideos.tv has a section with Endgame Simulations. Very useful!
ChessImager is a utility by Steve Eddins. It generates chess position displays so I don’t have to take screenshots and upload them.
