My personal opinion is that of many others on this forum. If it's your first brisket go with salt and pepper. Nothing more, nothing less. Again, just my opinion. They're still some of my faaaavorite briskets to eat, but my family prefers them doctored up a bit.
What I usually end up doing for them is some salt, pepper, onion and garlic powder, with some red pepper thrown in for a kick. I put the same ingredients into some beef stock and inject it as well.
The Life of the Knife is Ended By! The Wife.