There are two first-time-free paleo books:

Most of the recipes in this book have a huge amount of honey. But 
there are a few with no sweetener added. And every recipe has a 
picture. It is a rare Kindle book where the author has actually made 
the recipes in the book.

Paleo Diet Recipes: Most Wanted Paleo Dessert Recipes That You Will 
Love! by K. Reynolds-James
http://www.amazon.com/dp/B00BWZFEB2

This next isn't a paleo book, but the author gave it a paleo tag. It 
has four glowing non-specific reviews from people that have not 
bought the book. No doubt them were phony reviews.

Incredibly Delicious Chicken Recipes from the Mediterranean Region 
(Healthy Cookbook Series) by Vesela Tabakova
http://www.amazon.com/dp/B00BP9GO6Y

There are also a few 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