Waking Up is basically the attempt to find spirituality coming from a rational and scientific point of view. Very interesting read actually.
Demian is a book by Hermann Hesse, the same guy that wrote, Siddhartha, Steppenwolf und Narziß and Goldmund. He is very good in telling the stories of people with all of their aspects. In Demian he follows the childhood and puberty of a boy. Usually his books tell parts of his own life and the way he does it is fascinating.