Which is better nook or kindle?

I am going into college and they said i should be able to get my books on the kindle or nook. I need to know which one is better. i herd that you can share books on the nook and be able to borrow books from the library too. I want to be able to share books and a wide viartiy too. I'm only getting it for reading and college. not for apps and games and crap. Please tell me which is better