Nothing really prepares one for this experience. A long drive uphill to a gentle rolling prairie of grass and juniper trees. Pretty, but where are the canyons? And then, wow, you reach an overlook and OMG there they are stretched out before you as far as you can see. And this day I am just doing the Island in the Sky part of this huge wilderness park. Without a 4 wheel drive and back country skills, all you can really see is from the overlooks, but they are just so spectacular it is plenty for a great experience.
On my second day, I did the Needles southern portion of the park. Totally different and maybe even more amazing?