I might also suggest Avedon At Work In the American West by Laura Wilson which documents that project. Great, behind the scenes stuff! Coming face to face with those huge, amazing portraits during the original exhibit was definitely one of the most memorable shows I have ever experienced.
The Americans by Robert Frank is another great one. Recently re-issued/re-printed.
I have been also enjoying Annie Lebovitz At Work. It is an autobiography of how she got started and how she approached several of her seminal and most famous shots. Pretty amazing collision of talent, timing, and luck. For instance, she had a cover photo in Rolling Stone while still in Art School, and only mere months after switching her studies there from painting to photography. Wild stuff.
