Below you will find some non-technical books which I like.
The Analects, by Confucius and his disciples
Is there a God? Or, are there Gods?
The Varieties of Scientific Experience: A Personal View of the Search for God, by Carl Sagan
The Language of God: A Scientist Presents Evidence for Belief, by Francis Collins
Things A Computer Scientist Rarely Talks About, by Donald E. Knuth
Five Golden Rules : Great Theories of 20th-Century Mathematics--and Why They Matter, by John Casti
Mathematics: Its Content, Methods and Meaning, by A. D. Aleksandrov, A.
N. Kolmogorov and M. A. Lavrent'ev [Original in Russian, translated into many languages]
Men of Mathematics, by E. T. Bell
Chinese Characteristics, by Arthur H. Smith
Linux and Open Source
The Art of UNIX Programming, By Eric Raymond