Kaz Cooke. Definitely.
I loved Tracey Hogg's The Baby Whisperer, but I know a lot of other people don't.
I'm a ready kind of person, and I found pregnancy to be quite hard in that respect because every book felt so judgemental in its own way. No matter what you think or do, there is a pregnancy or parenting book telling you that you are evil.
So as hard as it was, I restricted myself to 3 books. Kaz Cooke's pregnancy book, Tracey Hogg's parenting book, and the What to Expect the First Year. The Wat To Expect book I *ONLY* used as a reference manual, and did not read it cover to cover. I'd have had a major freakout session if I had. But it was good to have for reference, especially for medical things.
Kaz COoke now has a book about Toddlers, and I'd have used that as my medical/reference manual if it had been published at the time. Will do next time.
Miriam Stoppard made me cry. Her book is the only book I've ever actually *burned*.