If I start to read before sleeping I would fall asleep ... well .. when I read a book to the end! :D
It is never easy to me to stop reading so I have to make a small agreement with myself whenever start to read- when I have to stop!, and I always try to postpone that ...a 5 min more, a 30 min more... I just adore books, and can read anywhere because I'm INside the book! :)