Well, it does sound like you are on the right track.
You might check the inside of the lid for flaky looking black stuff, if so hit it with a brush and a hose.
The food grills should probly get washed down with a little soap and water, then with laundry bleach, and rinse well.
The pork butt is a great first cook.
I like to trim off any large chunks of external fat. I tie it up so it's easier to handle. I like to use a bit of oil on on the meat before I rub, and then salt it a bit. You might proceed with caution here, if the butt has been 'enhanced', it will show on the label. If so be sparing with the salt.
Once the salt is on, I apply a generous portion of rub, wrap it up in saran and let it rest in the fridge overnight, but I get to cook all day long. Your circumstance may be different. Let it rest in the rub as long as is practical for your situation.
When I start the WSM stuff, I take the meat out of the fridge and let it sit room temp, while getting the pit ready.
I use a full ring of Kingsford blue bag, with 4-5 chunks of whatever wood buried in. I have a few fruit trees, so I use my own wood...apple cherry, plum, pear, sugar maple.
I light about 20 coals in the chimney and pour it on, then add another chunk of wood. (I like smoke). I then put it all together, with a clay saucer. If you use water, just be sure to replenish after 2-3 hours or so.The pit will hit 220 in about 1/2 hour. All bottom vents go shut, aiming for a temp 240-260.
The meat gets a bit more rub and goes on immediately when the pit is assembled. Probe in the meat, probe just inside the lid vent, which is wide open.
When meat temp hits 190 and steadily climbing, I will probe the meat with a fork. If it goes in AND OUT with no resistance, You're there. Off the grill and rest for at least 1/2 hour to an hour.
Pull,mix in that lovely bark serve with sauce of choice.
I am only able to concentrate on this 'cuz I am stuffed with first time attempt at Cornell Cheekon. Yum.
