I think that Secrets of the Baby Whisperer was by far the best book I read and I wish I had read it before I had given birth.
But, honestly, I've learned more from talking to other mothers (ones with grown children and ones with babies still at home) than I have learned from the plethora of books and self-help guides out there. Also, anything you really want to learn/know is already on the internet. Not a big fan of the "What to Expect" series of books--find them to be a better doorstop than anything--I've never actually gained anything helpful from any of them but they are a really popular buy for first-time moms. (All of mine were given to me by first-time moms who bought them and found them just as useful as I have). I've heard that "The Girlfriend's Guide to..." series of books is hilarious and a great, fun way to relax into motherhood but I haven't read them yet.
I guess, I never found myself too paranoid over anything in my son's first year, apart from the disastrous first six months until I picked up Secrets of the Baby Whisperer and got him on a good schedule. My husband, however, would be a good candidate for "set-your-mind-at-ease" baby books--well, he would have been in the first year but by now he's adjusted.
I have a friend in the States who took her baby to the emergency room so often she was on a first-name basis with the staff there--because every little thing she would over-react about. I guess it also comes down to personality then too, right?