Congratulations!
Prenatal classes are great for increasing your awareness ahead of the inevitable whirlwind of medical jargon you may experience. We did a Bradley Method[1] class and were planning a home birth, but discovered at 34 weeks that my wife and child were in a situation called "Placenta Previa" which predicated a cesarean delivery. I hope you never experience the terror and helplessness of watching the mother of your child (if you're the father; sharing the experience of a father) in pain, wondering what in the world is happening. I'm not saying this to scare you, but to say that learning as much as you can about birth is invaluable but only half the battle. There's no way to know everything, just get your bearings and find good sources and buckle up.
You will not be able to read everything, but getting the lay of the land of how birth works and what people will tell you ahead of time is incredibly helpful.
One thing I would say also about having my little guy about a year ago is that I would work on my relationship with my wife more if I could do it again. We have a lot of trust and we're fully committed, but having a kid takes almost all of your time for a long time. Sleeplessness, my return to work, her feeling of isolation and "confinement" for a time with him at home was hard on her and on us. I would encourage you to talk about those times, plan ways to get over those bumps, and get closer to each other. Other couples in our birth class talked about hiring a nanny to free up time and make things easier around the house. I thought they were posh and crazy, now I think they were brilliant and posh :)
Put the time in up front, get every help your system/insurance affords you - doula, pump, lactation consultant, pillows for the couch in the recover room - and drink it in. No matter how bewildering, scary, surprising, each and every individual moment may be, it is a beautiful time. Enjoy it!
[1] http://www.bradleybirth.com