Dude, read everything you can on BF and try to test ride as many bikes as you can. Don't be impulsive, you have a bike so take your time and buy something you know fits, feels good, and is in your price range. It can be done! I got my Trek a couple years ago and love it. I take it out all the time to run errands and go to work (when I'm working one of my side jobs). I took it last year on a 150 mile road ride from Plymouth to Provincetown, MA bone stock (regular pedals) and it held up pretty well.
Don't be afraid to ask questions either. The only silly question is the one that remains unasked.
Be careful though, its addicting!