Amazon has a list of classics that are always free. You can download them at any time for free. In addition, Amazon has a limited time promotional area of the website that lists books that are free for a limited time. Sometimes this books come and go in a matter of a day
You can bookmark this page to quickly check in on free Amazon Kindle Books. As of today, there are 279 titles available.
Hopefully this will allow you to find books quickly! No worries, I will continue to post the free books as they pop up, specifically the more popular titles.
If you are using a Nook, check out how to get Free Nook Books here.