The following books are totally free from Amazon (AMZN) in the Kindle format. If you aren't sure whether you want a particular book or not, you should probably go ahead and download it, because these special offers may not last long. I'm not sure how long these free offers will be available.
Trading Aces: How to Play the Stock Market...and Avoid Ruin (Trading Essentials) by Nick Johansen
BiggerPockets Presents: The Ultimate Beginner's Guide to Real Estate Investing by Joshua Dorkin and Brandon Turner
Fearless Retirement: How to Retire Without Financial Worry by Conrad Toner, Bruce McDougall, Sue Balcer and Joni McPherson
The Problem of Knowledge in Financial Markets by Paul Jourdan
The Little Book of Money: Book excerpts from Jack Bogle, Ben Stein, Joel Greenblatt, Louis Navellier, Hilary Kramer, Kathy Lien, David Darst, Michael Covel, and John Stephenson