I respectfully disagree with Chipper on the injection, especially for your first brisket. Keep it very simple... If you inject you won't know how well you did on the actual cooking process as far as moisture/texture and general flavor from your chosen rub.
I prefer a higher temp and no foil, but you can still accomplish a good finished product doing the opposite.
Lonestar 24" Vertical offset w/ Insulated Firebox & Performer Platinum
Former owner: Jambo Backyard, Klose BYC, Med. Spicewine, Pitts & Spitts, XL & (2) Med. BGE's, 22" WSM & (2) 18" WSM's, 18" & 22" Weber Kettles