There are six first-time-free paleo books:

Paleo Baking - Paleo Cookie and Bread Recipes | Amazing Truly 
Paleo-Friendly Recipes by Ben Plus Publishing
http://www.amazon.com/dp/B00FOREYOM

Fermented Beverage Recipes: Paleo Probiotic Friendly Fermented Drinks 
for Health and Wellness (The Easy Recipe... by Scarlett Aphra
http://www.amazon.com/dp/B00FW6ANV8

Paleo Crockpot Cookbook: Illustrated Paleo Crock Pot Recipes with 
Delicious Slow Cooker Soups, Stews, Dinners, Sides and Desserts 
(Paleo Recipes: Paleo ... Lunch, Dinner & Desserts Recipe Book) by Jane Burton
http://www.amazon.com/dp/B00FUZT89O

Paleo Breakfast Recipes: Morning Recipes for Delectable Cuisine (The 
Easy Recipe) by Scarlett Aphra
http://www.amazon.com/dp/B00FW6EZDU

Every Day Paleo Smoothies: The Complete Paleo Smoothie Guide for 
Every Occasion (Every Day Recipes) by Ranae Richoux
http://www.amazon.com/dp/B00FQMZM28

Paleo Recipes For Kids - 35 Paleo Recipes For Kids. Easy, 
Afforadable, Quick & Delicious Recipes To Satisfy To... by Emma Powell
http://www.amazon.com/dp/B00FP7P67A

There are also 14 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