I found some great articles on parents.com. One is about four easy exercises you can do to strengthen and stretch muscles you use during labor. Doing these can reduce pain and stress.
Exercises to help you prepare for childbrith
This other article is about things you can do, besides exercises, that will help ease labor. It suggests things like packing an iPod with your favorite music, getting enough sleep so you don't start out exhausted, and bringing a birthing ball. Doing some of these things can reduce your risk of an episiotomy and make you less likely to get painkiller.
How to make labor easier
I've been doing exercises, and I'm going to add a couple more that the first article suggested. I'm also going to do some of the other things in the second article, like bringing music and learning relaxation techniques. I hope this will be a great experience!