By websites I'm assuming you mean places to play poker. Full Tilt and Poker Stars are the most common if you're in the US.
Two Plus Two is probably the most popular poker forum. There's also a few subscription based training sites like CardRunners, Deuces Cracked, etc. Steve Silverman is a coach (although he doesn't put out many videos) at leggopoker.com.
I've never been on deucescracked, but as a long-time acquaintance (and poker foe) of Joe Tall, DeathDonkey and Jay Rosenkratz, I'd be surprised if it wasn't good.
I can still remember the exact moment back in 2002 or 2003 where I realized just how much than me better Joe Tall was. We were having a cigarette near the Foxwoods poker room and he reviewed the action on a few hands we'd just played in a 20/40 game, and he remembered them in more detail than me, but he also processed the detail differently to emphasize different aspects of my game.
I was a winning player but after that night I stopped playing for a month, did nothing but study books, analyze hands and sessions, and grind out math to see if some of my assumptions about lines against various hand ranges were correct.
After that I got a lot better, jumped limits, and ended up meeting DeathDonkey in a 100/200 game at Commerce and again realized I was outclassed.
I'd say I owe them a debt of gratitude, but I'm pretty sure I already paid it at the tables.
Didn't expect a response from you! All is excellent, except for the fact that I'm east coast now and the mixed game and limit game selection around here is worse than terrible.
Seriously though, I meant what I said about the debt of gratitude. Massive thanks.
http://forumserver.twoplustwo.com/