South Kaibab Trailhead
Start your journey by taking one of the free NPS shuttles to the trailhead (you can't park overnight). In the Summer, you should start very early (4-5) to ensure that you make it to the Bright Angel campground by the time the midday heat starts to take its toll (11am-3pm). DO NOT attempt this as a 1-day hike in the Summer months. While there are stops for water, you will not be able to carry enough between stops, and because of the dry heat, you will not realize how much you are sweating and will easily become dehydrated.
It is about 6.5 miles down to the Colorado river, with consistent amazing views the entire way down. As there is little shade, it is better to hike down the South Kaibab trail, and up the Bright Angel trail, where there is more shade and more water stops as well. There is a bathroom about half way down, but no stations to fill up water, so you must carry all of your water for the 4,820 feet down to hold you over until you ready Bright Angel campground.