I'm a little miffed by how much half the serious players already know about Cataclysm's content -- folks like me will be n00bs in what's ostensibly brand-new content -- but I'm still looking forward to a few more levels of soloing, and a good excuse to take a stroll throw the [now changed] Old World (ie, pre-BC lands).
Anyhow, once I do, Relevart's Moonkin Class Guide looks like a good place to start:
Welcome to Relevart’s Moonkin Class Guide! This class guide has been updated for 4.0.1/Cataclysm and is designed for the beginning to expert PvE Moonkin, although much of the information contained within transcends those boundaries. I hope you find the information that follows to be useful and if you find any errors, don’t hesitate to contact me. Thanks for browsing and may Nature guide your Path!