I have a lot of photography books, many specifically on Street Photography and Documentary Photography. So I'll occasionally recommend a book or two for those who want to know more about the genre....
Today I'd like to recommend The Social Scene.
It's an exhibition catalog put together by the Museum of Contemporary Art in Los Angeles for a show held in 2000, but I think the work lends itself to the book form well: it allows you to sit down and spend time with some great photographs that reward slow browsing.
If you don't happen to already have dozens of photography books on your shelves, it's a great way to get introduced to the "usual suspects" -- including photographers Diane Arbus, Brassai, Robert Frank, Lee Friedlander, Helen Levitt, Danny Lyon, and Garry Winogrand.
The kicker is that the essays included (by Emily Apter, Cornelia H. Butler, A.D. Coleman, Liz Kotz, and Max Kozloff) are excellent and valuable -- not filler as is found in so many exhibition catalogs.