If you go to Petra then you must stay at Tetra Tree Hotel! It's a 5-minute drive or 30-minute walk up (20 minutes down) the hill from the main entrance to Petra. The views from the rooms and the roof top restaurant are spectacular! You're overlooking the town and Petra itself. The rooms are spacious, clean and comfortable and have everything you'll need. Hussam, the manager, is extremely nice, responsive and helpful.
Vertalen