#1. "RE: UberNoob: Bought D5000 off Craigslist... How do I know if I got shafted?" In response to Reply # 0
If the outward appearance of the camera is good, it probably wasn't abused. The smudge on the lens may just be a fingerprint which will clean off OK. Put the camera on "Auto" and take a bunch of shots. If the auto-focus is working and the exposures are good, you're probably OK. The D5000 is a good camera to start with.