Where to stay and how to get around

Staying in a village is best if you rent a car. If you want to take the buses and trains Florence is your best bet. That is probably not where you want to stay so you could perhaps look at Siena as a home base. They have easy buses to several towns around toscana. Do you have Rick's Florence & Tuscany book? If not I would pick that up with a lot of useful information for the area.

I agree with Robert... you have a choice of many day trips from Siena. By bus San Gimignano, Montalcino, Pienza and Montepulciano. Sorrento is not in Tuscany but would be a great home base. By train it's 30 minutes to Pompeii or by bus you could ride along the beautiful Amalfi coast stopping in Positano and Amalfi town.

I've been to Florence twice. Stayed at least one week each time and never got bored. There are just so many day-trip options and convenient transportation from there. The sidewalks don't roll up at night either and the piazzas are full of music and lit fountains. Florence itself takes a good three to four days. A day-trip to Siena is enough to see the whole place. From Florence there are full day wine tours available that will have you leaving at 0900 and taking a scenic bus trip (or private driver if you wish) with a good dose of vineyards, lunch and sometimes also dinner. This would be a good way to see Tuscany for a first-timer.

Thanks for the suggestions..they are all very helpful.

Without a car: Florence With a car: anywhere you wish.
If you stay in some areas of the Oltrarno, it will feel like a village.