Hi celebritytracy, and welcome to cruise-addicts.
Yes, you are correct about the restaurants on Norwegian Jewel. I would say to definitely have a few meals in the main dining room, Tsar's Palace. It is about the most beautiful dining venue I've seen at sea.
Le Bistro and Cagney's have cover charges, and I've heard good reviews of both. I've been to Le Bistro on another of NCL's ships, and truly enjoyed.
If they offer Shabu-Shabu in the Chin-Chin restaurant during your cruise, I'd give that a try. Shabu-Shabu is a wonderful meal -- you are given a pot of simmering broth along with your choice of meat and vegetables to cook in the pot. I don't know if there is a cover charge for this, but it's worth it either way.
Of course, food and restaurant recommendations are highly subjective, but I hope this helps somewhat.