I asked the community here and bloggers in general to provide links to posts which gave clear, informative answers about Diablo 3 mechanics. Here are the submitted links.
Overview of controls in Diablo 3 and how skill slots are used.
A common FAQ to Diablo 3.
Diablo 3 is a social game, so here's your recap on how to be social!
When real money is on the line, account security should be your primary concern.
This site only has a few builds at the moment, but it is updated frequently and should prove useful when Diablo 3 is in full swing.
If you're looking for the best guide to making money in Diablo 3, you've come to the right place. Videos, podcasts, forums, walk-throughs... basically everything you need and the content is constantly updated to boot! Lots of guides to paypal setup, making money on the RMAH, and dominating the gold auction house are already implemented and waiting for you to try them out.