This worked for me. Light full basket of charcoal in one spot, let heat up about 10 minutes or so, when temp gets to 180 or so, close the bottom vent to about a quarter inch, then start closing the top vent until temp stabilizes at 225 or 250. On my PB24, bottom at 1/4", top at a little less than one, holds 225 pretty good. Will take from 10 to 12 hours to bring the meat to 205 or so.
As for rubs, I use Dizzy dust pork rub. How much is personal choice, we don't like it heavy with rub but mix in a sauce once its pulled.