It should run between 225 and 250 for an hour a pound. To slice it, let it go until internal temp is 190, to pull it, let it go until 195.
Trim the fat to about 1/4". Make a slather of 1 part Dijon mustard, 1 part Worcestershire sauce, and 1 part "better than boullion, beef" and put it all over the brisket. Put it in a big ziplock in the fridge overnight.
The next day, rub it with your favorite beef rub, and put it back into the ziplock and fridge.
Now, prepare the smoker and let the brisket stand at room temp for an hour. Put it on your smoker and let her go.