Grand Canyon was one of the few places we traded out of DVC for. We got a place in Sedona for a week, but drove up to the Canyon and spent one night in the park. The accommodations weren't anything spectacular; think basic 50's type motel, block walls, inside and out. OLD, but clean.
We drove in from the east the first time. There was a little flea market and a small overlook before you actually got to the park, operated by Native Americans. They charged a nominal fee and I'm so glad we stopped. It got us really excited for what was coming up.
While at the GCNP, we did the helicopter ride out to the east end of the canyon and back. We didn't do the Skywalk thing. It had just opened, and while things may have changed since, the time spent getting there and back to Sedona, along with what they were charging (to gain admission to the Skywalk you have to purchase admission to Grand Canyon West Legacy $70 something), and then another $15 pp for the park and ride, unless you wanted to drive about 15 miles on an unpaved road (umm...no thanks), made us decide that it wasn't something we felt we needed to do ~ especially when you aren't allowed to take a camera on the Skywalk.
Of course we also traveled along the roads of the canyon, stopping to see the magnificent views and ate dinner at the Bright Angel Lodge. The day we did the helicopter ride in Tusyan, we also went to the
National Geographic Visitor Center and Imax theater. We ate at Yippee-ei-o!! The Steakhouse. Great couple of days.
We took the long way back to Sedona, driving west along Historic Route 66 and making sure we went to Williams, AZ. DH had to stop at the Harley store and get the requisite t-shirt.
Back in Sedona, we made day trips to Montezuma's Castle, the Petrified Forest, Painted Desert, Sunset Crater, and Meteor Crater. Of course, we also spent lots of time driving through the Red Rocks of Sedona. We wanted to do the Pink Jeep tour, but DH's back started acting up and so we decided against it. Slide Rock State Park looked like it could be a lot of fun, but not in March.
Be prepared for fluctuations in temperature. We wore shorts in Sedona and it was snowing north of Flagstaff.
Whatever you choose to do, you'll really enjoy your trip.