While you do not need to register your book with the Library of Congress, it’s a good idea to get a Pre-Assigned Card Catalog Number, or PCN (http://pcn.loc.gov/), if you plan to sell your book to libraries. You will need to be a publisher to get one, but becoming a publisher is very easy. Basically, you need to name your company, have an address and register your company. ZDocs will also be happy to assist authors who do not wish to start their own publishing company.

A Library of Congress catalog card number is a unique identification number that the Library of Congress assigns to the catalog record created for each book in its cataloged collections. Librarians use it to locate a specific Library of Congress catalog record in the national databases and to order catalog cards from the Library of Congress or from commercial suppliers. The Library of Congress assigns this number while the book is being cataloged. Under certain circumstances, however, a card number can be assigned before the book is published through the Preassigned Card Number Program.

The following excerpt is from the Librarian of Congress, Mr. James H. Billington.

“The Library of Congress is the nation’s oldest federal cultural institution and serves as the research arm of Congress. It is also the largest library in the world, with more than 130 million items on approximately 530 miles of bookshelves. The collections include more than 29 million books and other printed materials, 2.7 million recordings, 12 million photographs, 4.8 million maps, and 58 million manuscripts.

The Library’s mission is to make its resources available and useful to the Congress and the American people and to sustain and preserve a universal collection of knowledge and creativity for future generations. The Office of the Librarian is tasked to set policy and to direct and support programs and activities to accomplish the Library’s mission.”

James H. Billington
The Librarian of Congress

You can get to the Library of Congress’s website by clicking here - http://lcweb.loc.gov