Read what you like, but my main gripe with these birth books is the illusion that you have a degree of control.
I had easy enough births, and read lots of book etc, but when the time was there, nature took over and I had no say in the matter.
For example, I walked and walked in circles when contractions started, that was not something I planned, but I later read it speeds up birth.....which it did 
But the whole birthing process was something that happened to me, not something I controlled.
You push when your body pushes, there is no stopping it, and no point in telling people when to push etc.
Honestly, reading about methods can make you feel more relaxed and in control, but ultimately it's not about your rational brain,and rational thought. Instinct takes over 100%
That is not a bad thing imo, for my second birth I thought "my body will know what to do", which helped me relax a lot