I'm a big fan of Dan Millman...
There is a movie as well if you haven't checked it out.
(edit: I guess someone beat me to it)^
There are a couple sequels to the book.
"Journey of the Peaceful Warrior" (my personal favorite)
and
"The Journeys of Socrates"
I also really enjoyed his books
"No Ordinary Moments"
and
"The Laws of Spirit"
and his seminar
"Everyday Enlightenment"
There are a few others as well but I haven't really delved into them
here's a list:
http://www.peacefulwarrior.com/store/dans-books