You electronically obtain the Kindle books through your library website & Amazon account, although my library also has an app called Libby that you can read the e books on any device. You return the books electronically from your Kindle & the library's website. The first off loads the book from your device & the second part actually logs the ebook as returned. My library has a default setting of 2 weeks. I have never had a late return book - so I'm not sure about fees. However, you get an email when your book is due to be returned in the next few days. The cool thing is you can return it, reborrow it, & it still comes up right where you left off. There are sometimes wait lists for more popular books. If there' a waitlist - when you return the book it goes to the next person on the list & you'll have to wait your turn to get it back. My library allows you to borrow 10 e books at a time. Though I usually only have one or two on my device. Go to your community library's website & see what they offer. I've really enjoyed the convenience and as much as I love the feel of real books - I also like knowing that I'm no longer killing trees for my favorite hobby. :)