The Thinking Woman's Guide to a Better Birth by Henci Goer is one of the most commonly referenced books by people who are interested in natural birth and want to share that interest with someone else (i.e., "what book should I give my cousin who is pregnant and wants to learn about her options?") I can see why. It's an excellent resource, full of useful information, conveyed in a way that is very acceptable to highly educated, intelligent women. It appeals to me, as one of those women.
You can see the table of contents and some sample chapters here.
My one caveat is that it is very information focused. It's not about how to make decisions from the heart; it's about how and why to make decisions from the mind. This is very helpful for people who need to persuade their minds to follow what their hearts are telling them, or who need to persuade family members or friends to support them in following what they know with their minds or hearts to be right for them. It doesn't encourage delving deeper. But that's what Birthing From Within is for :-)