First, sign in (or register, if you don't already have an account), go to the "My Account" page, and click on the "Manage Gift Cards for NOOK Books" link located in the box marked "My Account Settings." Enter your gift card information into the appropriate boxes and click "Save."
Now that your Gift Card balance has been entered, browse the Barnes & Noble NOOK bookstore™ on your desktop, NOOK®, or mobile device. You can make a purchase now, or come back later. Your gift card balance will be waiting when you return.
PLEASE NOTE: You can redeem Gift Cards and eGift Cards for NOOK Books or single issues of NOOK Newspapers™ or NOOK Magazines™; however, they cannot be used to purchase digital subscriptions.
Once you've decided what you want, click the "Buy Now" button. Any available Gift Card balance will be taken off your total first. If the amount of your Gift Card is less than your purchase total, the credit card you have on file (if any) will be used for the balance.