Originally Posted by KlondikeGeoff
When I've finished a book, go the Content Manager and delete it. I have done this with about five books so far with no problem.
Today finished another book and went to delete it, and oddly enough, found all those other books I had previously deleted were back again.
If they were books you purchased from Amazon they are in your Media Library and can be downloaded to you Kindle again. In the Content Manager look just under the name of the book for a label indicating its location. You should see Kindle, SD Card, or Amazon.