Unless you want to visit in Florida before or after your cruise...it would be so much cheaper to sail from NY or even Baltimore! No airfare or hotel to deal with!
If you would rather leave from Florida, then yes, consider booking your own flight and hotel..Southwest or Jet Blue. It is acceptable to travel the day of your cruise but more relaxing to get there the day before. When booking hotels, i start with the chains that I am familiar with but I do research all options.
The key is research!