Shasta is like doing the Trail Crest chute for about 4,000 vertical ft. with some flatter stretches along the way. It can be steeper and icy in places, especially just below and through the Red Banks, as Bobby wrote.
The season is over for Avy Gulch, you want to be on snow and its melted out now. This time of year, all the routes involve lots of loose talus that sucks, unless you're good with glacier travel and trained in crevasse rescue. Normally you avoid the glaciers during the typical climbing season.
I really like the Hotlum Wintun route on the backside, but for a first time ascent, I'd do Avy Gulch. You can practice self-arrest skills at Helen Lake with others. Unless you go with someone who knows the backside of the mountain. Route finding and campsite selection are key on the backside.
The info and links below should be helpful. For current conditions, gear, permits, etc your go-to source is 5th Season in Mt Shasta City.
August 22, 2017 at 10:02
Peak climbing season has come and gone on Mount Shasta. Rockfall events have been frequent and snow cover on the mountain has melted off significantly. The Clear Creek, Hotlum Bolum, and Hotlum Wintun routes are in the best shape for climbing at this time. Many people have still been having successful climbs of Avalanche Gulch, but this route is now subject to more rockfall than most other routes. From here on out, rockfall will continue to increase and good climbing will fade. As always, be sure to check the weather before you climb.
http://shastaavalanche.org/http://www.shastaavalanche.org/advisories/climbing-advisory
