All replies are pointing you in the right direction.
One thing to add... the yellow mustard helps the rub stick on there good, and once smoked you wont be able to taste the mustard. It also helps in forming a nice bark.
Definetly pull the membrane, its not hard to do. I cant stand eating a rib with the membrane left on. Its kinda like getting a bite of aluminum foil. Personal preference I guess.
While your yanking the membrane, also dont forget to trim the skirt, its the diagonal flap of meat (bone side) trim it off of there, rub it up and smoke it for 3 hrs... makes for good munchies or save it to put in a pot of Dutch's Wicked beans.
Also dont hurt to spritz every 30 minutes with some apple juice. Just do it as quick as you can so you dont lose too much heat.
Last but not least... keep a record of your attempt, Times, temperatures, etc. That way when they are done, you have a guide to either re-create your attempt, or make a change.
For example, say you did the 3-2-1 to a Tee, and the meat falls right off the bone, but you like it with a little tug. To change it you would adjust to a slightly cooler chamber temp, or shorten the time. After doing it a few times... you can get it exactly where you want it.
Good luck, take pics!! and let us know how they came out.
You can do it!
