Scott You will want to figure about 3 people per lb of cooked pulled pork per person plus 10%. So for 100 people I would figure about 37-40 lbs of cooked pork. So I would start off with about 80 lbs of raw butts. This will be about 9 to 11 butts. For sides figure 4-6oz of each side per person.
You can burn wood or coal, if burning charcoal I would still add a gew sticks of wood per hour. If you want to have them ready to eat at 11:30am I would start them at about 9pm the night before and if they are 8 to 9 lb butts they will take around 12 hours at 230 degrees this will put them done at 9am then wrap them in a towel and put them in a cooler to rest until time to eat. Cook the butts to an internal temp of 195 degrees.
If you have a small store bought smoker you may have problems cooking in the cold weather and wind. Good Luck