250 pit temp, smoke for 4 to 6 hours until the IT reaches 160 or so. Wrap in foil or butcher paper, your choice, continue the cook until the meat reaches 195 IT, at this point start probing the flat section (thin, lean end) every 30 minutes or 5 degrees of IT, until a toothpick can be slid in easily, like probing a tub of butter. Once you have reached this point, pull the brisket from the pit, vent the foil for about 10 to 15 minutes to allow the cooking to stop and the excess steam to escape, wrap in foil or foil pan if it is not already, place in a cooler wrapped in towels for at least 1 hour, 2 or more is better. Once the IT of the meat has dropped down to 160 (optimal temp for the juices to have been redistributed through the meat) or below, it is time to slice it and enjoy.
Have fun and most all have patience!