Syncing Kindle Books to iPad

I bought a book by John Ringo that had a DVD that contained all his books. I copied the DVD (which is allowed by the license) to my MacBook Pro. The books are in several formats including the one use by Kindle. Downloaded the Kindle app to my Macbook, added the books to my Kindle library and it works fine. Just got my iPad and want to load the books onto it. However, the Kindle does not sync the books. I assume that it will only sync books purchased from the Kindle store. The question is how to I get these onto my iPad.