If you bought one book that would help you understand what, how and why you use clicker training on a dog, this one will do it.
I'm not a professional trainer, but I've managed to teach dogs a new trick in a single session while waiting in a line. Seriously. This book will cover the dos and don'ts and set you and the dog up for success.
You need to invest your time in learning the training, because quite seriously, the dog will really want to invest their time in learning from you, so this book will help you set some attainable goals for the two of you and to realize them, or come up with a different method of accomplishing the goal.
Positive Reinforcement is a fantastic training tool. I tell people that I am a pez dispenser for treats if the dogs get it right... :)