Alex, the first thing you need to decide is what you are calling "brisket." Most folks around here think "Packer" when a brisket is mentioned. A lot of newbies though see "brisket" at the grocery store and it is in fact a trimmed "Flat" portion of the brisket, the hardest part of the brisket to get right. It will usually weight 5-7 lbs. It is a leaner cut of meat that gets its juices from melted collagen, not fat. So it has to be smoked to a high enough internal temp, usually 195F-205F, until it probes tender. I can't remember the last time I smoked a flat only. I used to braise them a lot to make pot roast, which is an entirely different animal.
The part of the brisket called the "Point" is less readily available, but VERY easy to smoke. It is full of fat and extremely forgiving. I rate Points as easy to smoke as a pork butt. They are usually in the 4-6 lb range and nicely marbled. Even a Select grade point will have nice marbling. Smoked to 195-200F, they make great, melt in your mouth slices. Or you can make "burnt ends" out of a Point. Lots of threads on burnt ends. I prefer to slice mine if I'm not cutting it up for chili or soup after throwing 3-4 hours of smoke on it. The issue with a Point is that it will fake you out that it is done. A Point can probe tender as low as 180F. Try eating it then and you'll feel like you're chewing a fatty piece of stringy meat.
The Packer is a big hunk of meat that contains both the Flat and the Point. The secret to a good packer is to smoke it until the Flat probes tender. The hardest part of smoking a packer is LEAVING IT ALONE IN THE SMOKER! It takes a while to be ready. You thinking about it, checking progress, etc, won't help it get done any more quickly, and in fact will set you up for failure. Heat, smoke, and time are the only thing that will make it ready, and that last factor, time, can drive you insane. The longer a hunk of meat takes to smoke tender, the higher your anxiety level may grow as you start thinking "I've done something wrong." "It should be done by now." "Why's it taking so long?" "I'm going to dry it out." An underdone Packer will taste tough and dry. An overcooked packer will be so tender it crumbles and can also taste dry. One done right will be tender, juicy, and delicious.
There's only one way to get it right: practice, practice, practice. When you get it right, it's wonderful. If you screw it up, make chili, soup, stroganoff, beef spread, etc. out of the leftovers. Trust me, I speak from experience, and ate a lot of chili, soup, stroganoff, beef spread, etc.