Go to Texasbbqrub.com, they have great info on smoking briskets, and try their rub it's outstanding. I smoked my first brisket last Sunday on my Weber kettle, and it was awesome! The brisket I got was 4.5 lb, and from what I'm told anything under 8 lbs., is a brisket "flat", which is basically the same but smaller. It took about 6 hours, using regular charcoal, and mesquite chunks.
I used a different way of indirect cooking as explained in Steven's books, I banked the coals on 1 side, with a small water pan on top, and the meat on the other, with a drip pan. I was able to maintain a constant temp of 200-220 degrees.