Have you tried plugging in your iPod to your computer to see if that works?
When you say you pressed all buttons, have you also tried pushing every button on the iPod down for about 10 seconds for a "code red" emergency restart? Make sure your battery has had a charge for then.
Also, if you do not have the lastest version of the iPod software, obtain it.
If this has been consistantly happening, even with these recommendations/suggestions, try restoring your iPod. In other words, grab your iPod Software updater and completely wipe out the iPod (charge it for at least 30 minutes first).
If the problem consistantly occurs, you have a hardware issue. If you purchased the iPod recently, you should be able to have it checked out for free.