I agree with Yogi and I have a basic Nook as well - the battery will last me a long haul AKL-LAX, longer if I am on one of the enlightened airlines with USB ports in the seats...B&N are hopeless if you do not have a US-billed credit card (previously you had to be physically in the US to download books) -this goes on a list of things they don't tell when you buy a Nook. I bought a cover for mine with a built in light because I find it hard on my eyes reading for long periods from a backlit screen + the backlighting sucks up the battery...
Through the power of Calibre (way more user-frendlly than it was early last year) I was able to shed the tyranny of B&N and now I mainly buy epubs from Amazon and use Calibre as my epub manager for compatibility and up/down-loading books into the Nook.
If you are into scifi/fantasy, check out the free library at
Baen Books Science Fiction & Fantasy - Home Page where there is a very generous distribution of free epubs, many of which you will see on the shelves of B&N and the like...