One of my favorite books, and the one that has probably influenced me the most as far as my thinking, is The Yellow Emperor's Classic of Medicine. http://www.amazon.com/The-Yellow-Emperors-Classic-Medicine/dp/1570620806
This book talks about the way we must live our lives in order to stay in balance. For example, you have to carefully guard your health in the winter time, because you have the least amount of qi then. I really felt I did not do this well enough when I kept getting sick this winter, and that's something I am trying to work on. But did you know if you don't rest enough and eat hot soups and eat nourishing food during winter, that sets you up for allergies during the spring?
Did you notice how I make people who are scared breathe in when I do the acupuncture? And how I watch your breathe and try to insert the needle on the inhale? I always feel out of harmony if I insert on the exhale, and so I pause and ground and center. This is because of this book.
It has so many insights that I've found to be true. Yet there's so much in here, I continue to learn from it! Check it out!