Congratulations! The best piece of advice I can give you for the big day is to realize that once it starts, absolutely EVERYTHING is out of your control. Just relax and go with the flow and try not to get upset if anything does go wrong since there will be nothing you can do about it anyway.
Also, make sure you get a chance to eat and steal a few private moments with your new wife since everyone that is there is going to want to talk to you both.