Super simple way to get all kinds of ebooks and audio books for free using your local public library.  You can check out books and have them download to your phone and read or listen at your leisure.  It's part of the public library system and might just save you a lot of money if you subscribe to services like Audible.  
Here's how you do it.
How to Get Books for Free:
1. Go to Overdrive.com
2. Create and Overdrive.com account
3. Download Libby the player
4. Go to your biggest local public library
5. Get a library card
6. Make sure to create and remember the PIN
7. Sign into Overdrive
8. Find your library
9. Add your library card
10. Search for titles
11. Borrow or put on hold
12. Listen!