A large section in the Diablo 3 official site is now available! I’m sure the majority of those that are reading this are pretty much veterans by now, but if you’re wanting some more content and info, you can head over to the Basics Game Guide section.
The basics section covers exactly what you’d expect: the basics. The sections include everything from “Choosing your Character” to “The Auction House.” In case there’s something you happened to miss, it’s all there.
There is also the Diablo 3 Basics guide on DiabloWiki.Net compiled by the players.