Ultimate guitar is a huge resource of user submitted guitar tablatures for virtually all music genres (even some that don't necessarily use guitar). I should point out that the tabs aren't all professional quality so often they should be treated as a rough guide - nevertheless its completely free and definitely worthwhile.
To complement their directory of tabs they also provide guitar and music focussed news, reviews and interviews.
There are also plenty of nicely presented lessons and ultimate guitar also has a strong community and forum involvement. Chances are you'll be able to find someone who can help you work out why you can't get the right sound from your effects pedal, and so on.