This is the order in which, according to Apple, one should go about attempting to solve a glitch in your iPod. If one fails, you move on to the next. So, a visual guide for number one (in Step Two you have to press both buttons at once and hold them down till you see the apple):

Number two just means: “Play it again Sam” (like plugging it into a different usb port in your computer)
Number three means: Restart the computer.
Number four means: Reinstall the software (preferably the latest iTunes version)
Number five deletes everything in your iPod so, so only do this if you really need to
http://www.apple.com/support/ipod/five_rs/index.html
…..Good Luck!