Be careful before buying a book. One of the ones that was free for me
yesterday became unfree a couple hours later. If you buy a Kindle
book by mistake, it can be returned for a full refund within seven days.
There is one first-time-free paleo book:
The Skinny Paleo Slow Cooker Recipe Book: Over 40 Gluten Free Paleo
Diet Recipes For Weight Loss And Enhanced ... by CookNation
http://www.amazon.com/dp/B00CD79U0E
There are also some 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