C. S. Lewis: A Biography of Friendship by Colin Duriez

The great writer C. S. Lewis was a complicated man with a troubled childhood, and he also had some strange relationships with women, but he was also a wonderful friend to people, such as Tolkien.  This comprehensive biography discusses his sad childhood, his complex and bad-tempered father, and his liking for older women.  It mostly concentrates on Lewis's friendships, however, and how they influenced him.  I found the friendship with the very Catholic Tolkien and their discussions about religion especially interesting.

This is quite an academic biography, and although the writing can be dry, it is worth reading.  Duriez certainly goes into great detail about Lewis's search for meaning and longing for joy, his conversion, and his academic career and writing.  I would recommend this to any C.S. Lewis fan.