Well, the other guys have pretty much covered it. But I'll still chime in on a couple things.
First, on safety generally. Your best investment in safety will come in the form of buying your chaps, eye and ear protection, and possibly a helmet/face screen setup. Beyond that, buy a couple books on tree work and timber falling. Even if you're not going to be felling tons of trees or swinging from ropes, you will get a better understanding of the "big picture" of trees and saws, felling and bucking, and all that, and you'll have something to read on the john when you get tired of your Cabela's catalog. Watch some of the good online saw videos (Ekka posts a lot of 'em on here), order some of the free safety videos from the saw manufacturers, and find the link to the Swedish (I think, maybe Finnish) chainsaw how-to videos that someone posted on here a while back (even though they're not in english, they're still plenty educational).
Second, learn how to maintain your saw with an eye towards safety. Keep chains sharp and tight, bars clean and true, and your saw running properly. Generally speaking, what is bad for your saw is bad for you, too.
Third, read read read. There is lots of information out there; some of it is actually worthwhile.
Fourth, do your cutting with a buddy whenever possible. Preferably one who knows proper and safe saw use, and agree between one another to be free to critique the other guy's technique. Oftentimes you'll see someone doing something unsafe that, from their perspective, seemed perfectly fine. It never hurts to have an extra set of eyes watching out for you and an extra brain analyzing what is going on. Plus, if you do get hurt it's nice to have someone there to help out.
And lastly, don't buy a garbage saw. We've all done it, especially starting out, because it's cheaper than buying a quality machine. Fifty bucks saved today is not worth it over the long haul, and you WILL end up buying the better saw eventually...especially if you keep hanging around here!
EDIT: A couple links to posts about the three-saw plan, which may be helpful to you as you reason through the "what to buy" phase:
Three Saw Plan #1
Three Saw Plan #2