The Grand Canyon photo gallery has lots of photos of the Grand Canyon at sunset - because that happens to be the time of day I visited!
The Grand Canyon at sunset is spectacular - even more than earlier in the day, if that's possible.
We used the Grand Canyon Tour Company to visit the canyon - while you can certainly drive there and explore on your own, having a guide the first time you visit a new place gives you a much more intimate view, with background information and side trips to places you'd never find on your own! (see the cave painting at the bottom of the page).
There really isn't much to say about the individual photos - There are several views of the same spot, but they change a bit depending on the light and the angle used in taking the photo.
Our guide took us to an area well off the beaten path, where a few ancient cave painting survive. We climbed into a cave in the side of a mountain (don't be too impressed - it was an easy climb, to about 15 feet above the path!) where we saw, not only the paintings, but some charred areas indicating the campfires used by the native people that resided there. (as a former anthropology/archaeology student, that kind of thing fascinates me!)