MAKE SURE YOU HAVE GOOD TREAD ON YOUR TIRES!!!!!! Stock tires will do just fine. I had 15k miles on mine last year and didnt air down from my normal mid 40's psi to see what the truck would do right off the highway onto the trails.
On the question about gear, I hate driving in boots, they dont give me the feel of shoes for pedal response so i drove the whole thing in skate shoes like i normally drive. You might need to throttle the truck some to get it to bite so I would recommend not changing a lot from your normal driving position so your control isnt too irregular from normal if you will be new to the conditions as well. Keep as few variables as you can IMO. IF i had needed boots last year, i had my snowboard boots in the truck. I got out a few times on trail when we had to stop and if the snow was deep, id just climb on my step board and jump to the front of the truck or just walk a bit in the snow. I wore a t shirt and light snow pants with vents on them while driving last year. But again, I can go without a jacket when its winter up here and be just fine.
One thing i personally and HIGHLY recommend is to buy a programmer for your truck with some custom 5 star tuning maps on it. It fixes the lag in the factory throttle response and will greatly improve your ability to react not only at snoball but any driving situation you are in.