No buyer or seller should be without McBride's book on ID of First Editions.  I use mine two or three times a week and I have been in the business for years.

Whatever your interest in books, first you need to know, "Is it a first edition?" You can find the answer in McBride's sixth edition, A Pocket Guide to the Identification of First Editions.

Don't Leave Home Without It: A great guide at book sales or browsing in a book store, and purchasing books from the internet. Why? In the book over 3700 publishers from 1850 to the present and the manner in which they have identified the first printings of their books are listed. A guide to first editions that is comprehensive and easy to use.

You'll know exactly what to look for on the copyright pages of books you are examining. And whenever possible, the author pinpoints when a publisher changed methods of identification as many have done and some have changed their methods several times during their publishing history.