In the light of recent developments in USA (goverment shutdown due to budget issues which resulted that all national parks and museums were also closed) we were extremly lucky as we managed to get into Grand Canyon just in the day before it was closed. Though with Death Valley we missed our chance. May be next time.
Unfortunately the picture is not able to show even a small part how it looks like in real life. From the route perspective it was really nice that Grand Canyon was the last canyon in our route. After this canyon others would not be so impressive anymore. Really. Not in the next day at least.
As usual everything is made for tourists. Employee on the entrance will guide you with best places to check. Every 15 minutes there are free buses to allow you visit the most remote points. Drivers before the stop tell passengers short info about the stop.
There are a lot of animals in the park. Though you shouldn't feed them and let wild life be wild.
Comparing to other canyons we visited, that was the most crowded. Even though we were there in a business day. It should be hell here during a weekend (: