I agree with demigod that for your first time out, get a stripped lower, a parts kit, stock, and a complete upper. The upper is easy to screw up. The lower is not hard to assemble. Stick to reputable manufacturers for the parts. Lowers come in all kind of rollmarks, and 98% of them are just fine, but make sure the one you're looking to get has a rep for being in spec. For heaven's sake, stay away from stuff by Hesse/Vulcan/Blackthorne; their stuff sucks. Stick with a good maker for the lower parts kit and upper- Rock River, Bushmaster, etc. Daniel Defense or BCM if you are willing to spend a bit more.
For handguards, unless you're looking for something special like a free float railed one (even then, a Daniel Defense Omega rail would work great), I'd just pick out some two piece easy install handguards.