I did a 4 1/2 pounder a couple weeks ago, my first try as well. I cooked it for about 5 hours at 225. I wrappred it after a little more than 2 hours, at the end I put it over direct heat for a few minutes to add a little more bark to it. Let it rest for 45 minutes.
It worked out well, but I will wrap it after about 60 to 80 minutes next time. I think it should have been a little more moist.