South Rim...forget the train ride from Williams..waste of money. The Trailer Village is a good campground. Two caveats: One, the ravens will peck holes in your sewer hose so only put it out when you're dumping or encase it in PVC. Two, don't be alarmed if you feel a 'bump' on one of your windows and look out into the eyes of a moose. They roam the campground and aren't too afraid of people. The south rim has IIRC, 5 shuttles that take you throughout the park. Their routes overlap so you can easily take them everywhere. Their website shows the routes. Be sure to see a sunrise and a sunset. You can get on or off the shuttles as you like. They're free, and you can pick one up at Trailer Village so you won't need your car. At Bright Angel, there's a easy hiking trail if that's your thing. Finally, take plenty of water. At the higher elevations, even though you may not feel thirsty, you'll still dehydrate if you don't drink. Enjoy the trip....Dennis