I forgot the security pattern selected during setup.

If you don’t have the passcode all you need to do is factory restore the device I found these instructions online on how to do that.

1. Press and hold the power button for 20 seconds to turn off the Nook tablet. Wait about 10 to 15 seconds.
2. Press and hold the power button, and then press and hold the “Home” (“n”) key will still holding the power button down. The screen flashes, and then the message, “Touch the Future of Reading” appears. The message disappears, and then the Factory Reset prompt is displayed.
3. Press the “Home” key to execute the factory reset. A confirmation screen is shown.
4. Press the “Home” key once again to confirm the reset action. The Nook tablet is deregistered from Amazon, and original factory settings are restored.

How do I wipe a book clean to use it?

How to delete all on my husbands nook to use it myself?