If this is your first brisky, I would suggest keeping it as simple as possible and take some notes.
1. Just use a little kosher or sea salt with some black pepper for the rub. This way you can see what the smoke and fat does to the meat for flavor.
2. Don't marinade or inject. Either of these can drastically affect the outcome of the meat and then you won't have anywhere to start for improvement.
3. The smoker needs to stay at a fairly stable temp, the lower the better, down to no less than 220.
4. Don't probe, poke, test, cut, or even look at the meat for the first 4 or so hours depending on the size and cut of the brisket. If you have a large packer that is bigger than 8 pounds, then you can leave it alone for at least 8 hours.
5. If smoking a packer, trim the hard fat (kernel or corn) from the point and leave the rest. This will give you an idea of what to trim next time.
6. Score the fat on the flat in a diamond pattern and smoke it flat side up.
7. LEAVE THE SMOKER CLOSED. Briskets are like caterpillars. Leave them alone and they come out beautifully transformed.
8. You can test for doneness by temp of 200-205 or by inserting a toothpick into the flat. If a toothpick goes in with very little resistance, then it is done.
9 Wrap the flat it in a few layers of foil and then in a big towel. You can put it in a room temp cooler if you want, but a towell will work by itself.
10. Let it rest for at least one half hour.
11. Meanwhile, chop the point up into small, 3/4 -1" cubes, re-season and sauce them in a pan and put them back in the smoker. Let them continue to smoke until they get a little "burnt" and enjoy.
12. Slice the flat thinly ACROSS the grain and serve with the juices that were in the foil..
13. Post up the pics.