There are a lot of threads on gear, but the top of the list that I would recommend for someone coming from out of state would be a copy of the big game regulations, and a blaze orange hat and vest. I see lots of folks come to Colorado and not follow the rules, most likely because they just don't know them. Other than that, hunting is hunting. Plan for days ranging from 70 degrees to 15 degrees and quite possibly snow, depending on location.