We are visiting my son who is studying abroad in Florence. We are want to go somewhere for a long weekend - Thursday (late afternoon) through Sunday. Any suggestions? We have been to Cinque Terre, Rome, Sienna before. Maybe somewhere new. Is Naples too far?
Have you considered Venice? You can train from Florence and a long weekend would be just about right.
I agree that Venice could be a great choice. Other possibilities include Pisa, Bologna, Verona, Perugia, Ravenna/Rimini/San Marino... or someplace in the countryside that is not a major town/city! it really depends on your interests, how "touristy" of a destination you want, and what you'd want to spend your time doing while you're there. Oh, and your budget.
Umbria is beautiful with great towns and villages. Best done with a car. I recommend Genius Loci Country Inn as a base.