How We Sleep by Matthew Walker
he is a Professor of Neuroscience and Psychology, and the director of the Center for Human Sleep Science at the University of California, Berkeley. He wrote this book about his studies and findings on human sleep, dreams etc. and especially the negative effects caused by lack of sleep.
I became interested in it after listening to his lecture done to promote the book from Talks at Google: https://www.youtube.com/watch?v=aXflBZXAucQ
its interesting but i havent read much yet.