When I was pregnant with Max, I read every single book we could find about pregnancy and infant development. I even read every book out there about getting pregnant, and then later about childhood development. I'm not sure when it happened, but at some point, I stopped reading, and it was the best thing I ever did as a parent.
It might have had something to do with the fact that Max didn't start walking until he was 18 months. I got tired of reading all of the things that my child should or shouldn't be doing at such and such month, and I was tired of worrying. As long as my pediatrician wasn't concerned, I wasn't going to worry.
Max has pretty much developed at his own pace, and I've learned to accept that about him. He lifted his head and sat on his own, much later than the books suggest is normal. And, he never crawled. He only started doing his ape-like shuffle at 11 months, when a lot of other babies have already started walking. Yet, he was able to throw a ball and stack blocks way earlier than what the books suggest is normal.
As a mom, I've realized children will learn new things in their own time and in their own way. We briefly forayed into potty training, to quickly realize that he wasn't ready yet. Just sitting him on the toilet sent him screaming. We were mildly concerned about transitioning him from his crib to his bed, but he did that on his own over Christmas. One day, he decided to sleep in a bed, and after that we never put him back in the crib. We don't have a problem with him getting out of his bed like some other parents do. The same thing happened with introducing a pillow, a blanket, a straw-cup, and now a regular cup, and pretty much every major developmental milestone.
The kid does things on his own, when he wants to. I suspect, that this will make it easier for us to parent our second child. At least we won't be worried about her doing things too late or too early. The pressure for her to live up to the expectation of the child development books won't be there. I've not read a single book about pregnancy this time, and I've only briefly skimmed the weekly emails I get about her development. I'm not even concerned about taking another birthing class.
Reading books about discipline however, that is a whole other story...