This is intended for informational purposes only. Selling books by mail is one of the "ideal" spare-time business ventures that can be operated from your home, and with minimal investment. However, there's a lot you must know about this kind of business; a lot to learn, a lot to understand, and a lot of common sense required. The first thing you need to know is where to get books - the kind of books - that sell best via mail order. Selecting your source of supply, deciding which type of boo.