we had our first 2 years ago.
i think you need to have a plan, full of contingencies. 
my wife and i attended a birthing class through the HMO... it was pretty good, but many of the details (and sessions) were about aspects of pregnancy other than the actual birthing process.  I think there were 3 - 2 hour sessions devoted to the birthing process. 
Now, I was there for my wife, and she wanted to go natural, BUT here is what happened.
water broke 4 weeks+ before due date. Start 24 hour timer.
Labors pains were mild for 8 hours until the baby turned and got wedged in the birth canal at an odd angle.
Onset of back labor. Very painful. None of the techniques were very effective. 
Wife was not dilating very well, due to early labor. Drugs were the best option.
About 14 hours into it, contractions were not progressing. Since we had about 10 hours left before a C-section would become necessary, we again opted for drugs.
Pain became very pronounced... Wife could not function. She has a high threshold for pain, so I know that we made the right decision to put her on the epidural. 
Eventually, 23 1/2 hours later, Adam was born healthy and very alert. A very tired, exhausted mother, but no c-section (its major surgery, and has serious ramifications for recovery and future births).
All in all, we are very happy with the way things turned out. Patossen (spell?) was NOT nearly as bad as we had heard. The Epidural still allowed wife to 'feel' things, just took the edge off the pain. 
So, for us, we had a plan, and E had decided that she wanted to do this naturally, no drugs, etc... BUT reality changed everything. Be flexible and make your plan as a series of contingencies.