A standard book of stamps from the U.S. Postal Service contains 20 individual stamps. In January 2014, first-class postage rates increased to 49 cents for standard letters, making the cost of a book $9.80.
A book of stamps can be purchased at any U.S. Post Office, or online at the USPS website. Several designs are available at no extra charge and include over 60 different themed stamps including holiday celebrations, historical events and people, and various other commemorations. All first-class stamps are now Forever Stamps, which means they can still be used to mail standard letters even if rates increase in the future.