I can't figure out how to do this from Fulton or Dekalb County yet (Cobb doesn't have overdrive). It still says coming soon but hopefully very soon. If you figure it out before I do, please let me know. Thx!
I figured it out for Fulton County!
Click Advanced Search (top left) then under FORMAT choose Kindle and put in a search term or just click SEARCH and all the books available in Kindle format come up. If a book is available it will say "add to cart" next to the Kindle icon (you may want to check the box next to "only show titles available"). Add the books you want to your cart, then click "Checkout" and "Get for Kindle" next to each book. It will take you to Amazon.com where you will click "Get Library Book" and it will be delivered to your Kindle just like any other book