Tried charging via USB on a computer?
Tried a reset yet?
Press and hold the Sleep/Wake button and the Home button together for at least ten seconds, until the Apple logo appears.
If that didn't help either, try restoring your iPad > iTunes: Restoring iOS softwa
Are you using an iPad charger? Any other charger such as an iPhone charger, other type of charger, or computer USB port, may not have enough output current to charge an iPad. You really need an iPad charger, particularly when the iPad is discharged significantly. Also, if it is discharged to less than 10% you should leave it undisturbed for several (>10) minutes before expecting to be able to see charging progress.