There is a ravenous online market for college textbooks. Putting up a textbook or any book for sale on Ebay is a snap. Simply enter the ISBN number, which is located on the inside cover of most books. The ISBN number can also be located on the back of many books.

The International Standard Book Number, or ISBN (sometimes pronounced "is-ben"), is a unique identifier for books, intended to be used commercially.

Ebay recognizes the ISBN number, and will automatically enter all the relevant data about the book, and in most cases add a picture as well.

Non Fiction Books with copyright dates of 1999 and newer normally command top dollar on Ebay.

There are people who look exclusively for valuable books in their communities. The book scout will scour thrift stores, local auctions and estate sales for books that may at most cost a dollar and resell for $40 and up per book. They are known in the book industry as book scouts. Book scouts are able to pick the cherries from stacks of books in just a few minutes, earning hundreds of dollars for a small amount of work.

If you are book scouting at thrift stores or local auctions keep this tip in mind. A good rule of thumb is anything that you cannot understand technically would be a good idea to purchase. There is virtually no downside to buying used books; the worst-case scenario is the book you purchased for 50 cents is worth that amount. Quite often the books will average $25 and up with and occasional $80 or $90 textbook.

Get paid handsomely and become a book detective selling used books on Ebay.