First thing to try is to connect it to a power source and try to do a hard reset. To do a hard reset Hold both the power button and the home button together for a couple seconds. If the apple does not pop on the screen after about 10 seconds your ***'d.
***'d = hardware repair
Alternatively..... Leave it plugged in for at least an hour and try again. (Just incase battery is drained)
P.S. U can also try another usb cable if u have 1