Perfect Hips Belly Dance Workout
I like this DVD by Michelle Joyce. It's a belly dance workout that uses real belly dance moves (not all of them do!). The movements are clearly explained so you can get the technique right.
This is intended as a fitness tool, not a belly dance class, but it would make a good introduction for absolute beginners nonetheless. My only complaint is that the explanations slow the class down. Once you've mastered the moves, you need an option to run the whole class through without pausing as your regular workout.