Community:
Here are some nice active community resources for discussing Minecraft:Please note that all of these are third-party and aren't hosted by us. We link them because they're great.
IRC:
#minecraft on irc.esper.net - Official IRC channel, run by Notch. (channel rules)
#MineCraftHelp on irc.esper.net - Help and support from community members.
#mcchatter on irc.esper.net - For general community chatter. (channel rules)
Forums and communities:
Minecraft forums (Official forums, Notch reads these)
World of Minecraft
Minecraft on Mod DB
Minecrafting.ru (in Russian)
Wikis:
Minepedia
Galleries:
The Minecraft Museum