Note: I'm aware the database is currently broken (looks like my old host deleted it... again) and the data isn't up to date. I have now moved (on March 24, 2012) to a better host and will fix and update.
World Cube Association governs official competitions and results.
Speedcubing.com has news, unofficial records, links, etc.
Wiki of Speedsolving.com knows a lot about speedcubing.
TwistyPuzzles.com forum/museum/shop with many builders/collectors of special puzzles.