Here is a selection of free real estate investing books offered by Amazon in a Kindle format. Get them now if you are interested, as the free offer for these books may not last.
Real Estate: The Sustainable Investment
No BS Real Estate Investing - How I Quit My Job, Got Rich, & Found Freedom Flipping Houses ... And How You Can Too
BiggerPockets Presents: The Ultimate Beginner's Guide to Real Estate Investing
Real Estate Investing: How to Flip a House as a Real Estate Investor
Flipping Houses Exposed: 34 Weeks In The Life Of A Successful House Flipper