Have you picked up a copy yet? What will you be doing first when you do? Did you buy the standard edition or cough up for the $80 Limited Edition or even the $150 Legendary Edition? Or perhaps you're not buying Reach at all?
Do check out our Halo: Reach review, while you're here. Brian has also written a two-part multiplayer beginner's guide to help you get started shooting people in the face. If the singleplayer campaign is what you'll be heading straight for, though, you'll want to check out Xav's story primer to learn about the Halo universe's backstory.