Thanks so much for the replies. A lot of people have said that the rides at Disney are tame, but when they say that they usually don't realize the extent of my fear of heights and rollercoasters. I'm happy to know the rides won't be too scary for me!
My sister is terrified of any "hill" in a ride. She is not afraid. She is terrified. She did okay. I took her on Pirates, which in DLR, where we were, seems to have a less gentle drop, and she was fine. Brike every bone in my hand, but was fine. She was also okay on Soarin, and I was not sure she would manage.
I do not know the extent of your fears, but I will say that if you skipped 90% of all "rides" in WDW, you would still be able to find a good value. There are hows, parades, fireworks displays.
There are attractions that are more of a glide than anything that could be considered a ride, and there is entertainment galore.
I would say that if you are going for the first time, do as others suggested. Check out the attractions on Youtube. Watch planning videos that are on cable, and ask folks here to help you plan your days so you can have a balance of entertainment, shows and a few attractions that are not at all intimidating. You can always determine your comfort level for others after you arrive and acclimate to the attractions that are "safe" for you.
I will say that my sister went on a few attractions that I thought she would be comfortable on, and once she saw that Disney Attractions are not Six Flags, she was okay.