Over at Slate, A.C. Grayling, the philosopher who edited the vast history of secular western literature to create a humanist bible, 'singles out five titles that, in their various ways, provide useful perspectives "on how to live a satisfying and morally good life."'
One of the five listed is The Greatest Show on Eath: The Evidence for Evolution by Richard Dawkins. It was included because it is an excellent book explaining the development of life on Earth by evolution; I'm not sure Grayling could have given Dawkins higher praise than including him among Aristotle and J.S. Mill as seminal reading for living a good life without god(s).
Having previously read a third of the book (still waiting for a chance to finish the rest of it) I can attest that it is supremely engaging and well written. The most entertaining and informative book on the subject that I have encountered, with a close possible second being The Ancestor's Tale, also by Dawkins.