In April, I camped at Mathers Campground at the South Rim Village for a couple of nights.   At 7000 feet, it was cold at night (only 29 F).   I was thankful for my down sleeping bag.  Down the hill from the campground is the South Rim Marketplace, and not far beyond that, the South Rim Trail which runs along the edge of the escarpment for 12 miles.   The South Rim Trail is mostly paved with a number of interpretative signs and viewpoints.  Where points jut out into the canyon, the trail also veers out to a viewpoint.

Parallel to the Rim Trail is the Rim Road.   A free bus service runs the length of the route and visitors can get off at any of the stops along the way along the road to the end at Hermits Rest.  Most vistors get off at viewpoints, walk out a short distance to the viewpoint, then return back to the bus stop.  Hikers can choose any distance they want and return by bus.   The colors and shadows of the Canyon change throughout the day so photographers can make their choices according to the light and weather.  I walked 10 miles along the Rim one day, going out to each point for the views.   Hopi Point was my favorite.   The road from the East Village to Hermits Rest is for buses only so the trail between the western points had less people.   Hopi Point juts out farther into the Canyon than the other viewpoints, affording views up and down the Canyon, with glimpses of the Colorado River, a green streak far below.  

The best hiking is down into the Canyon, but the Rim Trail is still worth doing.   Camp at Mathers and walk down to the Rim Trail.   Follow the Rim trail all the way to Hermits Rest and then take the bus back.   Along the way, you may find the area near the Bright Angel Trail very busy.   Just hike through that area quickly, climbing out to the next point where you can look back to see the lodges on the Rim and below you, the Bright Angel Trail winding down to Indian Gardens and beyond to Plateau Point.   Each viewpoint offers new vistas of the rugged landscapes below.   Bring your telephoto lens for this trail, then on the next day, descend into the Canyon and bring your wide angle lens for the real hiking adventure.