After all the tapping, touching, and swiping you do, your NOOK’s screen over time will get dirt and grime on it. It’s a good idea to regularly clean it off, not only so that you can see more clearly, but because if dirt and grime build up, the NOOK might not work properly—it may not respond to taps, or it may think you’re tapping it when you’re not.
Clean the NOOK’s touchscreen with a lint-free, microfiber cleaning cloth. Some cloths for cleaning reading glasses work well on the screen. Make sure that you don’t use chemicals, liquids, or moisture, or abrasive cloths on the screen, because you could damage the screen or the device itself.