This short little book is the best and easiest way to learn about Green Smoothies. It's a quick read, with personal stories that both help you understand WHY green smoothies are so good for your health, but also HOW easy it is to adapt green smoothies into any lifestyle.
There's an interesting section on Raw Foods, which is helpful for anyone who wants to try a raw food diet, as many raw food diets can fall out of balance if you're not careful.
Also, the accessible nature of this book helps you make decisions about other foods you eat as well, and you'll find yourself craving healthier options after even a short time drinking smoothies.
There are plenty of green smoothie recipe books out there, but this is a good one to start with - it's easy to read, but has great background information. You don't really need recipes after this.
You can read more detail on amazon.