Hello,
In order to begin using your used NOOK Simple Touch, you will need to first deregister your device so it is no longer registered under the previous user's name. Next, you will then have to register your device as a new account under your own name. Below are instructions for de-registering your NOOK Simple Touch.
To erase and deregister your NOOK, do this:
1. Tap the Erase & Deregister Device menu choice on the Device Info screen. Your NOOK displays a page for erasing and deregistering your device.
2. Tap the button labeled Erase & Deregister Device. A dialog box appears, asking you to confirm that you want to reset your NOOK.
3. Tap the button labeled Reset NOOK. Your NOOK displays a messaging saying it is deregistering itself. Once your NOOK has deregistered itself, it displays a message saying that it is clearing data. Once data has been cleared off the device, your NOOK reboots itself.
To re-register with your existing account, or to register with a new account, follow the instructions for getting started here under the Registration Support Section:
http://www.barnesandnoble.com/u/Support-NOOK-Simple-Touch/379003176?#40270-1
Remember, you can always visit your local Barnes & Noble store for assistance with these types of issues as well.
Thank you,
The NOOKTeam