Plug the ipod into your computer and bring itunes up. You should be able to restore it from there. You can also force it into recovery mode by pressing both buttons simultaneously until the ipod blacks out. Then let go of the power button, but keep the home button held down until you get a message in itunes about restoring the ipod. However, a restore is not likely to fix this problem because you likely did damage to the display when you dropped it, so it will need to be sent in for repair.