Have been trying to get back into the game lately since I finally live somewhere where I actually have space to set up a board, and remembered some of the good times we had playing online. I couldn't remember where it was, but after some searching, once again found the FICS (Free Internet Chess Server) which can be found at
http://www.freechess.org/ — their login is totally broken for me, but I never played using their site anyway. Instead, it's much more recommended to play using a third-party client, which turns the whole experience basically into the IRC of chess.
http://www.babaschess.net/ — It doesn't appear to be in active development anymore, but it's still the most popular client, and it still works better than the others I've tried. Give it a whirl! Pug and Ghandi used to play with me on there for a short while, and you can join chats and observe games and stuff ... a few times idol and I think maybe a couple other people joined us and we played some games and chatted while we watched others play. It was quite a lot of fun.
Anyway, just wanted to spread the love. My handle is the usual. Pop on and play sometime!
EDIT - Oh yeah, and I also found
https://www.chesscademy.com/ — basically attempting to be the Khan Academy of chess. It's free, and while there isn't a metric shit-ton of content, there is a fair bit there already, with more planned. You can learn the basic rules, learn some basic strategy, complete with tactical exercises, and move on to some more advanced stuff.
I should also mention that if you're actually interested in chess theory, FICS has lecture bots which give lectures on famous games and such. Announcements are made when you're logged into the server, and you can observe the games and ready the commentary that goes along with the games. It's pretty cool stuff, and worth a look.