I am using an original iPad that originally belonged to my wife. iTunes and Find My iPad recognize this device as Sally Fanta's iPad. How do I change the device name to John Fanta's iPad

You should be able to change it via Settings > General > About > Name, or when connected to your computer's iTunes by double-clicking on its name under Devices on the left-hand side of iTunes : http://support.apple.com/kb/HT3965

Look at this link.

Giving your former iPad to a spouse or family member: the quick guide

http://www.tuaw.com/2012/03/17/giving-your-former-ipad-to-a-spouse-or-family-mem ber-the-quick/

 Cheers, Tom 😉