A couple of my thoughts...
You will need to figure out how to tell the difference between a wild rainbow trout (non-clipped) and other trout as wild rainbows can't be kept.
I also believe that up that high on the Clackamas, bait (including nightcrawlers, powerbait, rubber-type worms, etc.) is not allowed, so spinners, spoons, flies, jigs, crankbait/plugs will need to be used.
As for fish cleaning, a search on youtube will get you started.
Good luck and have fun!