More Bibles have been printed than any other book. Although copies may be treasured by their owners, very few are of value to collectors. Of course, there are exceptions, such as the first English Authorised (King James) Bible and a variety of early Bibles that are sought because of some misprint, or other oddity.

Encyclopedias are normally only of interest while their content is current. Again there are exceptions, such as the first edition (1776) of the Encyclopedia Britannica.

Textbooks are rarely of interest to collectors. The exceptions are illustrated schoolbooks from before about 1850 and mint condition early editions of a few books that remained in use for a very long time, such as the American McGuffey Readers.

Collected works are usually published because an author is very popular. For this reason, large numbers are usually printed and they are unlikely to be rare.

Sermons and books of religious instruction are also usually printed in large numbers and, so, are unlikely to be scarce. A few such works were written by major figures in the history of religion or relate to historical events, and may be collectable for that reason.

While it is theoretically possible that an individual book from a set may be just the one that some other collector needs, the chances of finding the matching set are so remote that it can be assumed that such books are practically worthless.

19th and early 20th century fiction, unless it is written by a well-known author, is almost worthless. (If you are not sure whether an author is well-know, check whether he appears is a standard reference work, such as The Norton Anthology of English Literature.)

Book club editions are produced in large quantities, often using inferior materials, and are usually of little value. (Most book club editions have a five- or six-digit code in a small white box usually on the back cover – but be suspicious of any book that does not have a price printed on the dust jacket.) The same applies to Readers’ Digest Condensed Books.