There are a number of ways you can make money selling books online. Perhaps the easiest way is to use the services of companies like Half or Amazon. The online auction sites like Ebay is another possibility. They each have their advantages and strong points and it's really more a matter of personal choice.

1. You need to decide what you want to sell. Will you sell used second hand books, paperback or hardback books, rare out of print books, or popular titles? Will you specialize in fiction or non-fiction? You should decide your niche first and foremost.

2. Your chosen niche also needs to be one that people are already buying books in. Don't try to educate your customers into buying from you. Find a niche where people are already buying and tap into it. There's room for everyone, so don't let the competition scare you off. Competition means a healthy marketplace that you can make money from.

3. Find a source or several reliable sources for your books. You have to be able to buy them for less than you sell them for in order to make a profit. The cheaper you can buy the books and the higher you can re-sell them at, the bigger your overall profits will be.

4. Open an account with the company you intend to sell the books from (Half, Amazon or Ebay). You can of course sell books from more than one online book service, and this is probably a good idea too.

5. With the online book services such as Half you can check out the value of books before you purchase and try to sell them. Do a search for the ISBN number at any of the online book service providers. This will bring up a list of the books currently being sold by other vendors. Check out the prices being offered. Anything below $5 is probably not worth bothering with.

6. List your titles and the conditions of your books. Remember that Half and Ebay both use a rating system of user feedback. If you say a book is in good condition when it's not, your feedback will suffer and your future sales will therefore suffer too. Be careful and err on the side of caution if possible, but at least be honest when rating a book's condition.

7. Price your books as competitively as possible. This can mean pricing them low. However, if you can position yourself apart from the crowd and offer something different, something unique that gives your books perceived value, you can set your prices higher. Be careful though and set them too high.

Always be on the lookout for sources to find books. Flea markets, yard sales and garage sales can be good sources sometimes. Used book store can also be great places to find books that can be resold for profit.

One often overlooked source is library sales. These don't happen that often, but they can bring up books that are very saleable and often in good condition too.