Reading the book is an excellent complement to the movie
I saw the film first, but if anything the book was even better. A rare occurence that I prefer a format I've seen second to a version I saw first, but hey.
Anyway, it really answers some questions I had about the number of days they were in the desert, what happened to Carlos, and brought out more information and analysis of the characters. All the characters are the same except for their names in some cases, and Dorfman is an English designer called Stringer, but otherwise just the same.
"He's a bit of a rough diamond but his heart's in the right place."