I took those classes and never needed them since I had a c-section. There were some good info since I was having twins, but I also got some useless advice that would have set me up for some disappointment had I followed instructions.
Biggest advice I can give you. When the day comes, don't set your heart into a birth plan. It rarely goes as you'd want it to go. If you expect to go natural with no drugs. You might be surprised what you feel during labor and you may change your mind. Forgive yourself if you do go off your expectations. It's OK to change your mind no matter how badly you wanted to do something else. You may want your husband in the room with you. You may want only certain people visiting you. Things change. The point is, focus on the one thing that matters....you go to where you plan to have your baby and walk out of there as a family in good health. What happens during is of very little value when what really matters is you, your husband, and your new baby. It's nice to have the extra stuff that you have planned to make the experience as pleasant as possible and there's nothing wrong with trying to follow whatever birth plan you have thought up. Just don't expect to have it followed exactly.