What is Print on Demand (POD)?

Print on Demand Book Printing (POD)

Print on demand book printing allows you to pay for your books one at a time, only when your book is purchased. The quality of a print on demand book printing is not as good as offset book printing or even short run digital book printing in most cases, but it may be the best option for some people.
Submit Properly Designed PDF Files

You will still need print ready PDF files for POD printing so please consult with the printer to make sure the files are submitted correctly. There are fewer paper and trim size options, so please consult with your POD book printer before creating something that will not work. The biggest print on demand book printers are Create Space and Lightning Source. Familiarize yourself with their requirements if you are going to choose print on demand printing.
Quality vs. Cost

Using a print on demand printer will make the unit cost of your book higher than it would be if you used a short run book printer or an offset book printer. The benefit is you do not have to invest in an inventory of books. If you like the quality of the book being printed and are not in a position or not willing to invest in an inventory of books, this could be a good option.
Vanity Publishers Print on Demand Printing

If you choose one of the many vanity publishers that publish books today, be aware that they will mark up the print on demand price of your book substantially. Fully understanding the printing process is important before making any publishing or printing decision. Book printing is an area where these companies make a lot of money off of unsuspecting authors. For a good discussion on this topic, you should invest in a copy of The Fine Print of Self Publishing. This book analyzes over 40 self publishing companies and is a wonderful resource to help find the best vanity publishers.