The first pregnancy-related book that I bought was called "Bun in the Oven" by Kaz Cook. It's known as "Up the Duff" in the author's native Australia, and I find that title much more clever, though I suppose it might be just as cliché :) I bought this book because I was about seven weeks along and deathly curious about what on earth was going on inside my body (why was I so tired? Why did I feel nauseous for most of the day?) and also too chicken to buy a serious book like something from Dr. Sears or the traditional What to Expect. So, humour won out, and I bought Bun in the Oven.
It is a fun read, and a good starter book. I imagine that the humourous approach would appeal to fans of A Girlfriend's Guide to Pregnancy. There's a chapter for each week of pregnancy that outlines what's going on in the world of fetal development, and then launches into a discussion of nutrition, fitness, hormones, genetic testing, wardrobe needs, or other topical issues that women would have to deal with around that time-frame. Sometimes the topics occurred before or after they were relevant to me, but some people experience the same thing a few weeks earlier or later than others may, right?
This book isn't really one that will hold an expectant mum with a curious mind for the entire forty weeks, though. By week twelve, I'd picked up a more serious and technical one to supplement, and after that I got smart and began to start borrowing the books I wanted from the library (no offense to Amazon, though). But funny and light-hearted was exactly what I needed when I bought this book!