Just driving into this place your mind is immediately blown. The natural stripes and deep reds of the rocks are ridiculous! Also, crazy tall peaks and sheer rock walls. You will gawk at the beauty of this place, guaranteed.
Since it's just ONE slow road ONE way around the park (dumb design) you need to plan a little, so here goes:
I recommend stopping at Calico Hills first. It's just beyond the visitor center and this is your best chance to get up close and personal with the famous red stripey rocks. This is less of a trail and more of a rock scramble. You can get some great photos here.
Then keep driving through the park and enjoy the various look out points, but don't leave until you've done the First Creek Trail (the very last official trail head before you leave the park). It's a short hike and there's a pretty little waterfall that you play under. We've seen burros on this trail.
This park is well-worth a visit. Deducted one star because of the stupid one-way road that is the only was to get around the park.