There are two first-time-free paleo books:
You Can Afford Grass-Fed Beef! - The ultimate guide to saving money
by eating high-quality, local meat by Nicholas LaDieu
http://www.amazon.com/dp/B00DCJA1VE
This was has been free numerous times before. But not announced here.
Long ago I bought and then returned it to write a review. And the way
I check for new free books tricked me into thinking I had bought it
free in the past.
Paleo Breakfast Recipes (Paleo Recipes) by Tina Clark
http://www.amazon.com/dp/B006WSMY3U
There are also many others that were also free in the past. See:
http://www.amazon.com/s/rh=n:283155,k:paleo,p_n_feature_browse-bin:618073011&sort=price