Fenzi, Denise, and Deborah Jones. Fenzi Dog Sports Academy Publishing.
Book 1: Developing Engagement and Relationship. 2013.
Book 2: Motivation. 2014.
Book 3: Play!. 2015
Book 4: Focus and Engage!. 2016.
This series of four books covers the foundation needed for a successful working partner: engagement, relationship, focus, motivation, and play. All four books are full of "how to" information along with detailed case studies. The books are quite thorough in discussing many different types of dogs and how to connect with each them. Additionally, all of this foundational work is done positively and in a way that promotes a great relationship between you and your dog.
I highly recommend this entire series to anyone who is new to training a working dog! These books thoroughly cover the foundation needed to learn how to motivate, play with, and engage your dog. They cover the basic knowledge needed to do all these great things with your dog, knowledge that is not always directly taught at the Schutzhund club but is assumed the handler will "pick up" as time goes on. The motivation and engagement books in particular are my favorite!