We were at the Grand Canyon this past Summer. We drove there from Ohio. To experience the Grand Canyon you should really plan on hiking below the rim. My son and I hiked in from the South Rim and spent the night at the bottom of the canyon (Phantom Ranch). An amazing experience. It's about an 18 mile round-trip hike with an elevation change of nearly 1 verical mile-- so it is strenuous. My wife stayed behind at the El Tovar while we hiked in.
A shorter hike (12 miles round-trip) is a hike from the South Rim to Plateau Point. My son and I did that hike four years ago.
The problem you'll probably run into with the Grand Canyon is finding lodging within the park. It's probably a little late for that but you might get lucky. We made our reservations 13 months in advance. And if you're going to spend a few days there, you really should stay in the park. We stayed at the historic El Tovar on the South Rim and of course at the Phantom Ranch.
If you really don't want to hike that far into the canyon, you can always hike a mile or two in and then head back. There is also this:
: THE OFFICIAL SITE OF THE GRANDCANYON SKYWALK :
It's quite a drive from the park itself, but looks amazing. We didn't have the time to go see it this past Summer so I can't comment first hand.
Have you thought about a cruise?