If you are an Amazon Prime subscriber, you can check out one free book a month. However, Amazon doesn’t make it really easy for you to figure out which books are eligible to be checked out from the Owners’ Lending Library.
To see the list of books you can check out, search for “prime eligible” in Amazon Kindle Books.
If you find one you like, add it to your wishlist. Then on your Kindle, you can browse your wishlist and check it out.