I've never felt that BFW is really a guide to childbirth, per se. I think it is more of an emotional workbook geared mostly towards women who have already had a negative birth experience in a hospital setting. For many women who are planning a natural birth/home birth and particularly so if it's a first birth, IMO, there isn't much relevant info in BFW.
If you are looking for an actual guide to what happens during labor and birth then Ina's May's Guide is excellent, and I love it to pieces, but my absolute favorite birthing book to recommend to clients is called Active Birth by Janet Balaskas. My personal opinion and experience is that understanding *exactly* what is happening to your body physiologically will help your mind and heart to be calm and able to work through any pain/discomfort you might experience and Active Birth explains all of that in easy to understand detail.
Not knowing exactly what is happening to your body can definitely induce panic. Panic releases the "bad" kind of endorphins and suppresses the catecholamines (natural pain killers) your body produces.
One of my favorite things that I learned from Active Birth is that when a woman is in any position that puts pressure on her back or hips, it closes her pelvic outlet by 30%!!! That is a significant difference and can have a HUGE affect on her labor and baby's birth.
Anyway, her book is full of great stuff, and while it is scientifically sound, it also encourages women to dig inside and find a center. It is the #1 labor guide/birth book I recommend, followed by Ina May's Guide, then The Functions of the Orgasms and lastly (because it's really not for everybody) Birthing From Within.