That's a small butt. Anyway, I put the thermometer in the meat and leave it there. Reason being is I don't like a bunch of holes in my butt. One will do just fine. I don't like juices leaking out.
I drizzle some apple juice on my butt about every 1.5 or whenever I throw some more coals/wood on. I only smoke it till I get a nice bark and then I wrap it in foil, put in a roasting pan with some apple juice in the bottom, put the lid on and finish it in the oven.
After I get till around 190, I put a sheet of foil over the top of the pan along with a bath towel, and I let it rest for 45 minutes before pulling. This is a pic of my finished product from Saturday.