If you are writing a book and plan to self-publish it, at some time you will have to get an ISBN number to distribute the book to wholesalers and retailers. ISBN stands for international standard book number, and it allows you to register your book with Books in Print, the directory for published books in the U.S. An ISBN number is how bookstores online and offline keep track of books, so if you also have plans to sell your book on the Internet or in bookstores, spending a few dollars to get an ISBN number makes yours a legitimate published book that they can carry in their inventory.
Go to www.lulu.com or www.isbn-us.com. You can get an ISBN number from either of these sites for one book for far less than you can at other sites that sell ISBN numbers in blocks of 10 to publishers.
Have your book's title handy and your credit card.
Follow the screen instructions to secure your ISBN number.
Use the clip art they send you of the bar code and ISBN number on your book's back cover. Depending on the software you use, it will be a GIF or JPG file.
Each time your book is revised or has additional printings, you will need a new ISBN number. If you are using print-on-demand services, you will not need a new ISBN number for each printing, but if you make changes to the book, you will need a new ISBN number. Getting an ISBN number allows you to retail your book through hundreds, if not thousands, of outlets.
If you skip the ISBN registration, your book will not be able to be sold by the major book resellers. This could be a costly mistake in the long run just to save the $35 registration fee.