If you’re into audiobooks (ex. Audible) or ebooks (ex. Kindle) you should check out Libby. It lets you download both formats of books from your library for free.
Hennepin County at St Paul public libraries both appear to use it (I’ve only tried it with Hennepin). I just plugged in my library card number and PIN to get started. There isn’t an unlimited number of copies of the downloads so you may need to put a hold on some titles. It also allows you to filter for books available for immediate download. And, like audiobooks and ebooks in general, not every book is available in every media format.
For ebooks, you can search Libby for an ebook, then have it download your Kindle or the free Kindle app (which you can download for free to your phone, tablet, computer, etc. from your app store).