Easy, moderate, and difficult. We stuck with Moderate mostly. The moderates generally have no more than 4-500' ups and downs. 100s of miles of interlocking trails, fairly well-marked but not always so you need the trail maps. April seems like the best time, when all of the high desert (above 4000') plants are in bloom and the high mid-day temps are in the mid 70s.
Hiking poles and grippy boots are handy. Around that altitude, oxygen is not what it is at sea level (around 17%).
Sedimentary formations, red sandstone and limestone. Animals? Mule Deer and Collared Peccary. One rattler crossed the trail. Birds? That's another topic.
Posting a few pics. Only from the easy parts, because they are the only places I could safely grab my iphone while trying to keep up with our pals. We stayed at a very comfortable resort-type-thing.
Website now turns my vertical pics into horizontal. Annoying. From our deck - that's a seasonally dry stream with cottonwoods in the foreground. See my moon shot?
A few hike pics below the fold -