The first thing to try is reseting your iPod. Hold the Menu and Select (center of the click wheel) buttons simultaneously for about 6-10 seconds. The apple logo should appear for a while, and after a little bit it should go to your iPod's main screen.
In general, Apple has 5 R's for troubleshooting your iPod:
Reset, Retry, Restart, Reinstall, and Restore.
For more info, here is [http://www.apple.com/support/iPod/five_rs/iPod5gen/|Apple's troubleshooting page], as well as [[iPod 5th Generation (Video) Troubleshooting|iFixit's troubleshooting page]].