Among your books may be some old or unusual items. It may be useful to find out what their monetary value is for tax purposes, for determining a sale price, or just to know what they are worth. A professional appraiser can make this determination for you.
The Library of Congress does not provide this service. However, you can find a professional appraiser through the website of the Antiquarian Booksellers' Association of America, which features a Collector's Corner, advanced book searching capabilities, membership directory of appraisers indexed by subject and geographical area. You can also search for books on website of the International League of Antiquarian Booksellers , as well as obtain information about related events and the market for rare books. Auction catalogs are also an indispensible resource.
Other sources of information are listed on the website of the Smithsonian Institution, which includes a bibliography, professional contacts, and suggestions for selling valuable objects. It may also be helpful to check with universities, libraries and museums in your area for workshops, conferences, and other events connected with rare books.
Your Old Books, a pamphlet written by Peter Van Wingen, the former curator of the Library of Congress Rosenwald Collection of rare books, provides background information about appraisals, including frequently asked questions.