Here are some great websites that you will find indispensable for your guitar playing and musical development.
I don't normally like to recommend tab sites on the web (the tab is rarely right!) , but Tab Library is easily the best site out there. It has a vast database of songs on offer and what's more is that it's entirely legal - run by publishers, Music Sales - so you're not leaving the artists out of pocket. Ultimate-guitar.com works similarly in the US, paying royalties to artists .
Free music for classical guitar on Dirks Guitar Page by D.Meineke - Scores in TablEdit (tef), MIDI (mid) tablature and sheet music/standard notation (pdf) format - best database of free classical music on the web!
The leading monthly guitar publication, which is packed full of great song tutorials that are usually beautifully explained.
Not the most exciting website out there, but it will prove indispensible.
This is easily the best - and cheapest - place on the web to download official guitar sheet music.
This site has a great selection of ear training drills, ranging from the basic to the advanced.
An excellent online tutorial site, especially for electric players.
All information required for classical and acoustic grade examinations as well as diplomas available for different disciplines.
Information on grade exams and other music courses.