There should be a neat little catalog with that smoker, I have one myself. You really need the rib racks and the chicken stands. If not, do a google on Brinkman. You can order online and they are FAST!
I use a mixture of charcoal (use a brand you like with seasoned chunks, like hickory, mesquite, or whiskey flavoring) and water soaked smoking chips of the wood you like the flavor of..
If you get the chicken stands you can put an open beer (can) in the chicken, and smoke it that way. Moist, tender, flavorful, and delicious.
I make my own sauce, marinate my ribs overnite at least, and smoke them in the racks I bought from the catalog. With two full racks, one on each grill, you need about 3 hours or so to smoke them.
Most of those smokers have a temp guage on them, keep it in the middle of ideal or closer to hot. I added two vents to my smoker with shutters to keep it hot.
Another great thing to smoke is pork tenderloin roast. Get the ones with the little popup to tell you when they're done. Again, a good marinade makes it happen.
I also smoke marinaded venison in mine. Shoulder or ham from a good sized deer is excellent.
I tend to use Jack Daniels as a marinade, although a low priced burgundy is also an excellent choice.
The store bought marinades are a good place to START. Buy them and develop a recipe to suit your taste.
Beware gorcery store marinades and marinading wines, they can be LOADED with SALT. Enough to choke a horse to be exact.
Prepare to get fat. Or excercise a lot.
