I recently bought a used iPad and when I try to go into my iTunes account, the previous owners email comes up and it asks for his password. How do I delete his info and put mine in?

On my device under Settings/Store I can sign out one account and sign in with another. If this doesn't work, a hard reset of the device is another option.

A hard reset is just a reset that retains all data and settings, it doesn't delete anything. If you want to start over, you can reset it to factory default by turning off the iPad (not just sleep, but off), then press and hold the Home button as you plug it into a computer + iTunes. Release the button when iTunes starts prompting you about the factory restore/backup.

Or go into Settings | General where you can erase all content.

Thank you for clarifying that. I was using the term "hard reset" as I would for other mobile devices, meaning a total reset to factory and "nuke" of the device. I should have been more specific.