Hi mushymom.
I'm sorry, I didn't look at your profile before suggesting Jupiter, and didn't realize that you were a brand new diver. (Welcome to ScubaBoard, BTW.)
Being a new diver, I would forget about boats out of Stuart (if there are any). Boat diving from Stuart is a long way offshore, generally a little deep, and the currents usually run very strong. It's not beginner's diving. Others may disagree, but I would suggest getting a few dives behind you before doing Jupiter also. The reefs run a bit deeper in Jupiter than Palm Beach.
My suggestion is go to West Palm Beach. (You'll hear it called Palm Beach, West Palm, Riviera Beach, WP, WPB, PB, etc.; it's all the same place.) There are plenty of nice dives in the 45-60 foot range there.
The other place to recommend is Boynton Beach, just south of West Palm. Similar to West Palm, just shades of difference in the reef life. Biggest difference I find between WP and Boynton is the way the operators run the dive. In most cases in WP the whole boatload will go with one float ball or flag led by a divemaster. In Boynton, multiple small groups of 2 to 6 are sent off, each with their own flag. Also, in WP most boats (there are exceptions) will mandate a profile, while in Boynton they just say dive your own choice of profile (following your tables or computer) up to 1 hour max.