The first thing you need to do is download the free Kindle app for the Google Play Store
From here you need to open your newly downloaded Kindle app and either sign in to your Amazon account or create a new Amazon account
Next you need to open the options menu of the app. This is the icon which consists of three horizontal lines, that can be found in the top left of the screen, once here select Kindle Store
Now you’re in the Kindle store, all you need to do is select Books > Kindle eBooks and then sort them from Price: Low to High. This will then show you all of the free books that the Kindle Store has.
It’s also worth using the Filter More option in order to narrow down what sort of book you are looking for. You can filter books into the following categories: New Releases; Genre/Category; Author; Avg. Customer Review.
It’s as simple as that.
Note: You can also save books to Amazon’s free cloud via a traditional PC and then access them on your Android device by selected Options > Books and then clicking on the book that will appear on your virtual bookshelf screen