OK, you have noticed the strange behavior of your iPad / iPad 2 / iPad 3 or even new iPad mini / iPad 4. It tends to freeze for about a few seconds every minute or is running too slow or something else. This is probably the best time for the hard reset of the tablet. To make things easy follow simple sequence:
Be sure that hard reset retains all data and settings on iPad, it doesn't delete anything. If you want to start over and delete all personal data from Apple tablet you should use iPad Recovery Mode.