Looking at Photographs, by John Szarkowski

Why?

"I think one of Szarkowski's things was he wrote all these wall labels, pictures at the museum over the years, really well." 
- John Loengard, Photographer

"I urge you to get a copy of this book. It is a selection of 100 photographs from the collection of the Museum of Modern Art with 100 short essays, less than a page each. John is simply the best writer there ever was on photography."
- Joel Meyerowitz, Photographer