Coin stores sell coin books. You can search eBay. But you really need a literature dealer if you want literature. And in addition, we all know Whitman and Krause as publishers, but DLRC Press and J. T. Stanton also publish. And there are many small numismatic publishers as well. I searched the ANA Dealer Directory for those who listed "Literature" as a specialty. I got this list. A To Z Stamps & Coins LLC (Phoenix, AZ) Alan David Workman - Bookseller (Saint Petersburg, FL) Classical Coins (Goleta, CA) David F. Fanning Numismatic Literature (Columbus, OH) David Sklow - Fine Numismatic Books (Colorado Springs, CO) Charles Davis (Wenham, MA) The Southeast Asian Treasury (Dunn Loring, VA) Telesphere Numismatic Corp (Larkspur, CO) Xavier Coins & Currency (Mesa, AZ) Ye Old Coin Shop (Young Harris, GA) Missing are George Frederick Kolbe and Fred Lake. Here in the East, John Burns makes many shows. I see him at MSNS in the Fall. We also have MSNS dealers in new literature. But there is a difference between new and old literature. Of those listed above, Davis, Fanning, Sklow, Kolbe, Lake and Burns deal in old literature. Their sales catalogs are a walk through numismatic history. They know the actual market values of the myriad old titles. The best way I know of to get to know the markets is to subscribe to the E-Sylum maillist. Start at th E-Sylum page here from the Numismatic Bibliomania Society website. And on that page, find the Subscribe link to the left. I get it as an email once a week.
Mike Marotta Telesphere Numismatics is out of the coin business, his inventory was bought up by some outfit called collectons, I might have been his last customer, I ordered the r4 r5 attribution guide by Edgar Souders from him, about two or three weeks ago, I am still waiting for it, but he explained he was going to be out of town for a few weeks so I am not worried.
Probably not very well known but one of the best IMO - http://www.killerstartups.com/Site-Reviews/gradybooks-com-orville-j-grady-numismatic-books-website Get on his email list and you'll have first shot at all of the new stuff he gets in
Grady has a website on one of the book finder links as well. He doesn't do internet much. He is out of Omaha, nice guy. I have bought from him. Good lists, especially adding Kolbe and Fanning, (the two firms are now combined effective a few months ago), to the original list. While the auctioneers deal with "old" books, remember that old is relative, really meaning second hand. I have bought both year old titles as well as 100+ year old titles from many of the firms listed, especially Kolbe. While I like to buy new titles to support research, I was not collecting in 1911 so I have to buy those second hand.
It can be hit or miss because some of the items are a little junky, but some of the older and/or out of print stuff I have gotten from this vendor. And after finding an item this seller lists on ebay, many times I can get them cheaper via his sales portal on Amazon. http://shop.ebay.com/numisbooks33/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686
Try numislit on Ebay Cheetah. It is Charles Davis. http://shop.ebay.com/numislit/m.htm...=1&_trksid=m194&ssPageName=STRK:MEFSRCHX:SRCH Not much right now but he sells there regularly.
I try to buy one book at every show I attend. We should all do a little to keep the literature guys in business. I also have purchased some books directly from Kevin Flynn, who was nice enough to autograph them.