Chianti

If you stay in Florence while renting a car, be aware of traffic restrictions in the historic city center. Make sure you choose accommodations where you can drive in and out, and preferably with parking on premises. I can suggest some areas just outside the perimeter of the ZTL (Limited traffic zone).

When you rent a car, you should drive along the Via Chiantigiana (SR222) to Siena then come back up on the freeway with a couple of stops along the way, like Monteriggioni and San Gimignano.

The Chianti Classico Wine Festival in Greve, September 7-10 might be just the thing for you (http://www.greve-in-chianti.com/en/2010_wine_festival.htm). A week later there's a wine festival in Panzano (http://www.panzano.com/important-dates/important-dates-eng.htm)

Greve is 18km south of Florence on the beautiful SR222. You can easily visit the hill town of Radda, which is just 20 minutes or so south.

We stayed at Castillo di Verrazzano (http://www.verrazzano.com/en/), which is just north of Greve. This is a wonderful winery and they offer a winery tour and a great food and wine pairing.

Unless you have a designated driver, I suggest you look into either taking the bus from Florence, which is easy, or hire a private driver if you plan on taking full advantage of the winery or the festival.

I like the Sagrantino Wine Trail in Umbria, stay in Montefalco.