A:
I was puzzled by this as sell, as the Nook showed that I had 250 megs available when new. I downloaded about 140 books from my Nook library, and the Nook indicated I STILL had 250 megs of memory available.
Several posters on the internet have said that the Simple Touch reserves 750 megs of memory for book downloaded from your Nook library and that the OTHER 250 megs of memory is for books that are "side-loaded" to your nook from other sources, such as books from the public library. The side loaded books are not kept with "My Library", but are kept in a section named "My Files".
Of course, micro SDHC chips have become quite cheap, so adding an 4gb card for a few thousand more books does not cost much,.