Thanks everyone for your replies! And buzzman, thats a nice checklist, thanks, I feel a little more confident now that I know at least what I should be looking at to make sure everything is in good running order.
A few more quick questions though..
How can I tell if the frame is too big for me, is it just the 1-2" below the crotch thing, or do I need to check how long that same bar is relative to my torso?
How do I do a quick check to see if the wheels are true?
Thanks again