You CAN freeze jerky, but like BBQ Mikey sez, it doesnt last long enough to worry about doing that.
If it is properly dried, it will stay good out on the counter for a week or so. I store mine in the frig in zipper bags with a paper towel to absorb any moisture.
Brisket has too much fat in it to make good jerky.
I buy bottom round or arm roasts when they are on sale. I freeze them for about an hour, then slice them a quarter inch thick across the grain. Cheapest and leanest cuts are best.
I marinate them overnight in plastic bags in a mixture of soy sauce, worchestershire (?) sauce and teriyaki sauce.
If you are in the States, I buy spices for my "Slim Jim's" (hamburger) from NESCO. I buy the Original for my SO and the hot and spicy for me.