I was talking to one of the girls at our 4-10pm sewing group about Kindle book readers. She told me about these websites where you can find free ebooks!
The main thing to be aware of is that sometimes the books are only free for a limited time. If you click on the book to buy it you need to check that the price is still zero.
This one has a list of free books plus links to other ways of finding books for free. The list is updated every day at least There are also email alerts available.
This is Amazon's list of their top 100 free books. It's worth trawling through.
Amazon - Top 100 Free Kindle books