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You can register from the Nook directly. Follow the on-screen instructions after viewing the welcome video. (or hit "skip" on the video page to go straight to the instructions).
Select If you are ON campus, select "MIT guest" for the wireless network. At home, select your own wireless network.
For more settings, on your computer go to http://www.barnesandnoble.com/, My Account/My Nook Library.
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