
OverDrive Media Console is my favorite way to read ebooks for free. The app syncs with your local library system, which provides access to a massive inventory of ebooks, including current bestsellers.
OverDrive is free to download and use, and works on all major devices. You will need a local library card to set up an OverDrive account. Once your account is created, login and select the ebooks you’d like to borrow.
OverDrive downloads your chosen titles to your preferred device in one of two ways: Via your Amazon account to your Kindle (or other device that uses the Kindle reading app); Or directly to your device for reading with OverDrive’s own reading app, Libby. I prefer the Amazon option because it lets you sync your borrowed ebooks across all your Kindle-enabled devices.
Checkout periods for OverDrive ebooks differ among library systems, but are usually 14 or 21 days.
Amazon Prime Reading is a quasi-free ebook option. “Quasi-free” because it’s an often-overlooked benefit of being an Amazon Prime member.
Prime Reading is the much-less-flush sibling of Amazon’s subscription-based Kindle Unlimited. Prime offers a changing selection of over 1,000 titles you can borrow. And throws in one free book (to keep) every month from a limited offering of new Amazon releases.

A third option, Amazon Kindle Unlimited, is the big daddy of ebook reading, with over a million titles, including hundreds of thousands of books generally not available at the library. A paid service (currently $9.99 a month, with the ability to cancel anytime) KU isn’t free, but if you read lots of books it’s a bargain.
Like OverDrive, Kindle Unlimited is a lending service, so you aren’t getting an endless number of ebooks to keep, but to borrow. Unlike OverDrive, however, KU isn’t likely to have as many big-name current bestsellers on its “shelves.” But there are plenty of popular titles along with a slew of books by worthwhile lesser-known authors.

A caveat: lots (and lots and lots and lots) of KU books are self-published or from very small publishers. Many are excellent, but there is a fair amount of terrible stuff. And don’t depend on Amazon reviews or “bestseller” lists for guidance. The self-publishing world has spawned a cottage industry of practices to boost sales rankings and generate Amazon reviews. But at least with Unlimited you can return stinkers after a few pages and download something else.
Both Amazon Prime and Kindle Unlimited offer free trials. You just need to make sure to cancel before the end of the trial period to prevent a paid subscription from kicking in. Canceling is easy, however, through your Amazon account.