There are a bunch of good tips in here.
Brake well ahead of when you'd normally brake until you get a good feel for the RV's braking. Those beasts can take a while to stop. Slow down more for turns, and make wider turns. Never put yourself in a position where you need to back up (e.g if you're parking, make sure you can just pull forward somehow, drive around the building, etc.).
Driving one gave me some appreciation for what it takes, and now I don't bitch about old people and their RV's nearly as much anymore. 😛