I would add:
1. Don't peek too often. It can increase the cooking time a bunch.
2. Be prepared for the "plateau" when the internal temp on butts and briskets hits about 170F and sits there for an hour or more. Be patient, it will go higher.
3. Spraying the racks with a bit of cooking spray will help in clean up.
4. And ditto what GeiyserQ said about the drip pan. Forgetting it is not fun and is really embarrassing (especially the second time.)