MacBook Pro no longer recognizing any devices

Hello,
Within the last week my macbook pro stopped recognizing all my devices, including printer, camera, scanner, and ipod. It also doesn't recognize the internal webcam. What could have happened, and how can I go about fixing this? I'm not terribly computer literate, so please pretend as if you are talking to your grandmother about computers. Do I just need to update the OS? I tried downloading the most up-to-date software for my camera to see if that would help, but no go. I have no idea if this is a software problem or a hardware problem. HELP!