I own three, count em', three books from the What to Expect Series. I own, What to Expect When You're Expecting, What to Expect the First Year, and What to Expect the Toddler Years.
These books are considered to be the definitive tomes on their subjects. And they really are great. They even tell you about stuff that is unusual.
They are broken down by month or months in the case of the Toddler Years and end with a few chapters by subject like Twins in the case of the When You're Expecting book. Generally the chapters begin with information about what will happen and then goes into a series of questions/answers. The information is awesome.
But there are some draw backs to the series. 1) some of the questions are similar so some of the answers are similar 2) a lot doesn't change month to month so some of the information is repetitive for example: morning sickness typically lasts three months 3) because a lot of the information is the same, they often refer you to another part of the book. I'm forever flipping backward or forward to find out the information that I need. 4) they are constantly updating the series so there are several new editions. You really don't need to go out and get a new edition for the general information. If there are any concerns about something new that you've heard, it always best to talk to your pediatrician or ob.
Other than that the books are great. Check em' out. I got my books through Book Mooch but I know that my local library has them too. (Reading Rainbow song has just gone off in my head LOL)