If you're considering a natural birth, the books by Henci Goer are fabulous. She wrote one, "The Thinking Woman's Guide to a Better Birth", for a lay audience. The same material is covered in much more depth in "Obstetrical Myths Versus Research Realities". The title is somewhat off-putting, I admit, but the book is just priceless. Far and away the most useful and important book I read while pregnant.
I didn't attend any in-person classes, so I can't comment on that, but I did use a self-hypnosis home study course (Hypnobabies) during my third trimester that proved to be remarkably useful. I credit that course with my fast and easy natural birth.
The cure for anything is salt water: sweat, tears, or the sea. -- Isak Dinesen
I would second (or third) an endorsement for the Sears' books. They have a Pregnancy Book, and a Birth Book. Once baby is here they have several books that may be of interest regarding parenting issues. You can take a peek at askdrsears.com as they cover all the same issues (in less detail of course) on the website too.
I also endorse the Henci Goer books and you might also find Pushed by Jennifer Block an interesting read. There is also a website pushedbirth.com.
I like What to Expect's Q&A format. I also LOVE "The pregnancy journal"- avail on amazon. I have used it for all 4 pregnancies and it is really fun to look back and compare them to each other. Also full of cool info about what's growing each day. It was recently revised and is even better now.
ResidentMom<br /><br />"If you bungle raising your children, I don't think whatever else you do well matters very much." --Jackie O.
AH yes! How could I forget The Pregnancy Journal by christine harris. I used it for my 1st pregnancy and am using it now too. I do go back and compare my entries and the printed daily info is very interesting and informative.