I posted this in a different thread a while back, but I don't think I ever got around to posting it here. If I did, sorry for the multiple posts. One of my all time favorite books is by the primatologist Sarah Blaffer Hrdy called "Mother Nature: Mothers, Infants, and Natural Selection". It's an amazing run down of everything that happens biologically from conception on through bonding with the new baby. She takes an evolutionary approach, so she explains things like why babies don't do well left alone to sleep at night (this would have been a death sentence in the age of large predators) or why post partum depression might have evolved (in some cases it prevents bonding as way for the mother to see if investing in a particular offspring at a particular point in time is worthwhile). She discusses all the hormonal changes that occur during pregnancy and lactation and discusses the biological roots of these processes. Pretty darn cool.
Obviously, since the book is written by a biologist, not all of it is fuzzy and warm. She talks a lot about how common infanticide is and discusses how, as much as we consider motherhood natural, it can be very difficult for many women, particularly women in difficult economic circumstances. I love it so much, mostly because I love understanding what exactly is going on in my body and what the purpose of these crazy hormones is. It's pretty long, but for those of you who like geeking out to biological stuff, it's a quick read. She also talks about monkeys a lot, and who doesn't love to read about monkeys?