Just some things from my chess favorites list for anyone still coming here that wants similar content...

http://chess.emrald.net is a free site that gives you a rating based on your success/failure to solve chess puzzles. It is timed to prevent cheating but can really help with basic pattern recognition. It isn't good for really deep type puzzle solving, but it will help your game.

http://www.chesstactics.org/ has a lot of chess tactics explained and a way to practice them.

http://www.chess.fm has lots of free content with top level chess players talking about various opening strategies as well as simply doing things like reviewing/annotating GM tournament games. I think there is also more content if you subscribe, but I don't know what more you get.

http://www.bookup.com is the main site for the Bookup openings software package. It has several different versions, but ultimately it is probably the easiest and fastest way to practice and become proficient with a given opening. It doesn't teach theory, but it is great for memorizing and learning the moves.

http://www.homestead.com/Observer/Openings.html is a free encyclopedia of chess openings. Not terribly exhaustive, but if you want an overview of a particular opening it is a very quick way to find it.

http://www.chesspublishing.com is another free opening theory site.

http://www.eudesign.com/chessops/ is yet another free opening theory site.

http://www.entertainmentjourney.com/index1.htm is a site with a suggested study regiment to follow that he claims can bring you up to a 1900 rating.

http://kd.lab.nig.ac.jp/chess/tablebases-online/ end game tablebases for your chess engines.

http://www.redhotpawn.com lets you play slow chess over the Internet making a move only once daily (or even less often). Up to 5 games concurrently for free. More concurrent games plus the ability to join clans and tournaments and such if you register ($29.95/yr I think).

http://www.chesscafe.com has lots of chess book reviews and several regular columns on various chess topics.

http://www.jeremysilman.com also has lots of chess book reviews and several regular columns on various chess topics.

http://chess.about.com/library/pal4/ztrapsqa/blztraix.htm has a bunch of chess traps listed as games with a viewer so you can follow them one ply at a time.