There are certain technical books that are considered classics - the Ansel Adams Camera/Negative/Print trio, the Henry Horenstein Basic Black& White Photography and Beyond Basic Photography volumes. Depending on your interests, there are plenty of other technical books worth owning, from Theresa Airey's Creative Photo Printmaking to the Tim Rudman books on Lith printing if you're interested in silver gelatin enlarging. If alternative processes are your bent, the Christopher James Book of Alternative Photographic Processes and the John Barnier Coming Into Focus volumes are good overviews. Gordon Hutchings' Book of Pyro is a great volume on using Pyro developers for film. Dick Arentz' Platinum and Palladium Printing and Sullivan and Weese's The New Platinum Print are single-process must-have books if you want to print in platinum/palladium. Depending on your interests, you can go really far down the garden path into specific areas like wet plate collodion.
There are too many good books to even begin listing studio lighting tomes, so I won't even try.
When it comes to photographers, ignore the herd and collect work by people who interest you. Spend time in your local bookstore - I'm sure there is an equivalent in Boston to The Strand/Moe's/Green Apple/Second Story Books that has a broad and deep photo section. If you see something that perks your interest visually, buy it and keep looking it over to understand what it is about it that attracts your interest.
Here are three of my personal favorites.
Latent Image (Beaumont Newhall)
The Tao of Photography (Philippe L. Gross and S.I. Shapiro)
Highway: America's Endless Dream (Photographs by Jeff Brouws)
Please refer to this thread, or even merge:
I would also recommend a few basics to buy on the cheap used:
Horenstien's B&W photography
Looten's on photographic enlarging
Introduction to photography by Rosen
Langford's Starting photography is another good primer, nice illustrations
Apart from the obvious Ansel Adams's set, The Negative, The Camera and The Print ...
I can recommend The Art of Photography: An Approach to Personal Expression by Bruce Barnbaum
Here's another one I would recommend. John Hedgecoe's "The Manual of Photography"
The question is to broad to get a right answer. If you are interested by the technical aspect of photography, yes the AA set is a must have.
If you are more interested in pictures, there is no clear answer, it depends on you taste. Due to you avatar, I would recommend the Diane Arbus Aperture monography. ;)
I wrote couple of times on the internet about books with photography as a main subject, but I try not to mention technical ones.
In my opinion photographer should seek for books in which photography is a process or way of life.
La Nuit américaine
The Big Picture
These are examples, if any of you like it, I'll write more. :)