There are a large number of great websites dedicated to Go; from online Go game servers to information about the history of the game, from online learning guides to archives of "Go problems" to be solved.
Here are a few site which we recommend especially:
The Wikipedia page on Go is an excellent source of information on all aspects of the game; from the rules of the game to its long history, from the equipment used for playing Go to reflections on the game in cultural and scientific contexts.
GoBase.org is a massive repository of information on all aspects of the game, including articles about Go, regular Go problems to be solved, Go software and news from the world of professional Go.
In their own words Sensei's Library is a collaborative web site about and around the game of Go. The site features an exhaustive glossary of Go words, phrases, players and much more. Pretty much everything to do with Go is listed!
For an up to date list of regional, national and international Go organisations, try the International Go Federation or else the following page from GoBase.org. Why not contact your local Go club to find out if they organise regular game nights!