I was in your position two years ago. I had no idea what to buy, kept hearing "compare components groups", couldn't decide on Hard Tail, Disc Brakes, blah blah blah.
First and foremost, I wish someone would have told me how worthless Full Suspension is around here. Sure, when I'm feeling lazy I like taking out my FS, but there is no reason to have one in the QC other than to impress chicks on the bike path. Yeah that's right, I rode my FS on the bike path. :banana:
If you have a grand to spend, you can get a pretty nice HT (and this is where most people will say compare "component groups"). Most of your mainstream bike manufacturers are priced similar to one another. One might have a slightly cheaper brake so they can put a slightly better rear derailleur and vice versa, but the fact is they are almost the same bike.
The bottom line is: Stick with a HT SLED and go ride every one that each LBS has. Don't worry about making the perfect purchase, because there isn't one. You will get yourself a good bike that you can build your skill set, learn what the term "component group" really means and HAVE FUN with.