The area near the headwaters of Deep Creek where the stream passes through the town of Running Springs on it's way to join the West Fork of the Mojave River in the high desert is a beautiful mountain environment, somewhat spoiled by the sort of easy access that leaves areas like this in Southern California littered with trash and occasional graffiti.
There are two developed climbing areas, Deep Creek Narrows, and Aztec Pond. Both areas are strictly trad, Deep Creek Narrows is part of the Deep Creek Preserve, and no bolting is allowed in either area.
The rock is fine-grained granite, and good weather for climbing can be found from spring to winter.
Not sure if there's an in-print guide book for the area, but if you can get your hands on a copy of Brad Singer's "Hidden Treasures: Rock Climbing in the San Bernardino Mountains" (not the one that's currently in print), there's excellent information to be found there about this area.
Check individual areas for directions to the crags.