They show an organization to all the things I've learned trial by fire, and for freaks like myself who like clear direction within a creative, open and safe environment, they really do fill in some gaps.
Sigh, so if you're a new parent or you're going to be. You might want to check out your local community college and sign up for their infant and toddler class now. Do the pre-school one further down the line. Seriously. It's amazing what you learn -- so you know the right questions to ask, so you understand you're not insane and so you realize that you're not alone in your endeavor down the crazy line of work that is parenting.
Seriously, worth it.