From Adams to Stieglitz: Pioneers of Modern Photography - Nancy Newhall

http://www.amazon.com/From-Adams-Sti...=Nancy+Newhall

How to Look at Photographs - David Finn

http://www.amazon.com/How-Look-At-Ph...at+Photographs

And, while not criticism, it is a good read:

Celebrating the Negative - John Loengard

http://www.amazon.com/Celebrating-Ne...g+the+Negative

... and others already mentioned.