Prenatal classes are totally worth it (if they're any good)
I'm a very practical and "gears and mechanics" kind of guy. I understand stuff best when I see things in action, but with parenting and especially concerning the birth, there's no practice run, so as a first-time dad I felt very unsure. Going to a prenatal course helped immensely. The classes described the whole birthing process in very small and surprisingly un-gory details.
There were exercises for the couples, designed to handle the contractions, and I think it's very important that the father takes part in these because it very clearly shows the mother that the father takes it seriously and provides support - and knows how to support.
There were also some practical demonstrations of things like infant CPR, diaper-changes, and so on. The classes were held by two midwives and it was clear that they really knew what they were talking about, and that they cared to make the whole thing easier on the couples.
There were also visits to hospitals (in Austria, these visits are called stork parties) and it was helpful for me to see all the facilities. The bedrooms, the delivery rooms, and so on. Visiting several different hospitals also made it very evident what the differences between them were, and I was surprised at just how different they can be. These visits helped us choose a hospital we felt very comfortable with.
I think prenatal classes are always a good idea, even if you are somehow certain that everything will happen perfectly. Just knowing what to expect helps immensely to remain calm throughout the whole event, and you'll be less stressed and freaked out if things don't go as planned.