I've been an avid hobbiest baker for over 20 years, and sourdough had always been a frustrating mystery. It didn't work, or it didn't work right, and every article and book I read seemed to have conflicting advice. Even the great James Beard's otherwise wonderful "Beard on Bread" was of no help. (James Beard, despite his many talents, didn't have a clue when it came to sourdough.) I just KNEW that sourdough had to be more workable and reliable, or the commercial bakeries that produce sourdough bread couldn't survive!
Ed Wood's book, World Sourdoughs from Antiquity, cleared up the mystery for me. His techniques work, they are understandable, and they don't involve witchcraft or the phase of the moon. While Dr. Woods sells sourdough cultures he has collected from around the world, his techniques will work with any culture, even ones you captured yourself.
The book not only tells you how to use sourdough, it explains what it is, gives an interesting history of sourdough, has amusing stories about how Dr. Woods collected the starters he sells, and has a number of very good recipes.
As I write this, there are four more loaves of sourdough bread in the oven, and the smell is driving me crazy.... before Ed Wood's book, I hadn't had any real sourdough success!