Just finished Dad's Guide to Pregnancy for Dummies. An easy and very informative read, covering everything from conception (though I'm apparently already an expert at this), through all three trimesters, the birth itself, and some of the earleist weeks of caring for a baby. Amber has observed that it actually has more useful information than her own girlie pregnancy book!
If you don't like much reading, or paying, there's also the cheat sheet.
Some random interesting facts I learned:
Most people know that it's good to read to your baby - it helps them associate with your voice, plus they start to recognize speech patterns. What I didn't know is that it's also a good idea to mirror the baby sounds that your baby makes. By repeating their sounds back to them, they start to understand the cause and effect of the sounds they make.
I'd heard of cesarian sections, and natural birth. I'd never heard about vaccums or forceps. Or knew that they can mess with baby's head. Or, if the head gets into a weird shape, you need to have your baby wear a special head-shaping helmet 23 hours a day.
You want your baby to feed for 10 minutes on each breast, because apparently the most nutritious part of the meal comes at the end.
And the one scariest thing I read: postpartum psychosis. WTF, my wife was a 1% chance of going into paranoid psychotic episodes and will try to kill me?