When I visited years ago on a school trip, we also visited Meteor Crater. From what I remember, it's basically a smaller hole in the ground (You can see the other side.) that really gives perspective to the immensity of the Grand Canyon. Here's a link to Meteor Crater:
http://www.meteorcrater.com/Visitors-Center-Overview
If I ever go back, one thing I will not do is take pictures. I remember taking dozens of pictures of these breath-taking views, only to be disappointed at seeing how the photos really don't get it across. This is something you can only really experience by being there. If I ever go back, I would just savor the experience, unburdened by electronics and thoughts of who I'm going to show these great photos too.
GingerK - I hope you have a great time!