Let it charge while attached to your computer for a while. Say, an hour. Then, while it's plugged in, if it still hasn't booted up, turn hold on, then off again, then hold Menu+Select for about 30 seconds. If that fails, repeat. Try that 3 or 4 times. If the iPod is still functional at all, the Menu+Select will work, so long as your fingers don't wiggle too much. And yes, I actually mean 30 whole seconds, use something to time it. It should take less, but that's assuming everything happens as it should.