If you are willing to go just a bit north of Fort Lauderdale to Lauderdale by the Sea or Pompano, you'll find some really nice shallow reefs that are perfect for newer divers.
I tend to use South Florida Dive HQ (they have daily trips to shallow sites) or call Gold Coast Scuba and they can help arrange details. Gold coast also sponsors shore dives. Other good dive ops include Pompano Dive Center and Scubatyme: if you choose either of these, just make sure they aren't visiting deep wrecks on the days you plan to dive