Just last week a friend asked us the same question, here is the tick list we gave 'em. They were interested in moderate trad and harder sport, and they never had vistited the awesome RED ROCKS of Utah.
In order from driving through the park. It’s a big one-way loop, and the cliffs I listed will be in your guide. There are several guides available.
Second Pullout (yes that's what is called)
The Black Corridor (Upper and Lower - both are good)
We've done most the routes here, all are worth doing. One pitch sport climbs grades 5.9 to easy 5.11. Can be in the shade as the corridor is narrow, but routes near the end should be in the sun. At lower on your left three new routes not in the Select guide go at 5.11b, 5.10c, 5.10A (facing wall right to left at the mouth of the corridor - all were awesome.)
Sweet Pain Wall (could be in the shade - afternoon?)
Routes are hard, but Sweet Pain is awesome 12a
Sandstone Quarry Area
The Running Man Wall Area (sunny)
Some really awesome sport climbs here, we only had time to do a few.
Red Heat 5.10C
Plastic People 5.10B (funky, but awesome)
White Spring (sunny?)
Tunnel Vision 5.7 trad, six pitches - popular get an early start.
Group Therapy 5.7 trad, but pitch two is really 5.8, six pitches just to right of the route above. (not many do this route, a good choose if Tunnel Vision is too crowded)
Dark Shadows Area (shade, could be cold)
Dark Shadows 5.8 trad, four pitches - awesome - rap the route
South Fork of Pine Creek Canyon
Cat in the Hat 5.7 just a couple moves mostly 5.5 & 5.6, trad five pitches. Rap route, fun, easy approach. Popular start early.
Juniper Canyon, Rose Tower (should be sunny most the way)
Olive Oil 5.7 trad, awesome route, removed and usually no one on this climb. Approach beta is wrong, hike straight up at drainage and stay on right side in gully. Longer approach allow 40-45 minutes. Walk off so you have to climb the entire route, unless you want to leave a lot of gear! Get an early start.
The Nightcrawler 5.10A trad, take some big friends. Awesome, rap route, longer approach, 45-60 minutes.
The Black Dagger 5.8 trad - did not do this route, but our friends did and said it was really nice. This is a cool area up this canyon and slope.
Oak Creek Canyon
Solar Slab, 5.6 trad, nine pitches - come early very popular, walk off
Beulah's Book 5.8 trad, I remember climbing three pitches and rapping - can finish up Solar Slab
John Nevada 5.9, trad this route is just to the right of Beulah's and is not in the select guide.
All three of these routes are awesome - and in the sun I think.
Best thing to do is a long route first thing in the morning and if you have time left over hit the sport walls at the top of this list. Black Velvet Canyon will be too cold I think so I left it out.
As for hiking the big ditches - both are awesome. Wish I was heading out.