Gearbox's Borderlands 2 is shaping up to be a great co-op shooter, if early impressions are anything to go by. It's still a month out from release, but you can pre-order it on PC via Steam. If you've been subsisting on trailers and screenshots, here's something new to digest: The official manual, which is live, right now, on Steam's content servers.
Update — 12:40pm: And now it's gone! If it appears online elsewhere I'll update the post. Update — 12:54pm: I've added a few screen caps of the manual. Update — 12:58pm: Google's web cache still features a HTML version of the manual.
If you hit up this link, you'll be sent directly to the manual, in PDF form. At 37 pages, it's fairly meaty, but this includes the list of credits, legal disclaimers and the contents page. But that's nitpicking — if you're keen to get a head-start on your fellow players, have a read of the document and please, if you spot something that Gearbox has yet to mention, make a point of it in the comments.
Borderlands 2 manual [Steam, thanks Okeefe]