Personally, I like Wikipedia - granted, it's not the most accurate, definitive reference on the web, but it's a bloody useful tool for finding out about stuff quickly (and the range of things it knows about is positively amazing - I looked up which tram I should catch to get to Essendon the other day).

Now, comes Wookieepedia... wonder if I can look up how to get to Tatooine from St Kilda?