One of the concerns I had before we left from Tuscany was about driving in Italy. I hope this helps others who are thinking about driving.
We rented from Hertz and picked up our car at the Rome (FCO) airport. This was easy, there are plenty of directions to follow in the airport to get to the rental area.
I ordered an Italy/Greece SD card for our Garmin and pre-loaded most of our desinations before leaving home. This was a godsend. When we picked up the car, we just selected our agriturismo in Greve/Greti from "Saved Places" and we were on our way.
We spent part of the trip to Greve on the A1 Autostrada. From Rome to where we exited was 11 Euro in tolls. We set the Garmin to kilometers and watched it and the speedometer. The speed limit is 130 km/hr. We ran 120-125 in the right lane. We passed some cars and others flew by us in the left lane driving much faster than 130, although there are numerous traffic cameras.
Be courteous on the Autostrada and you'll be fine. If you overtake traffic in the left lane and someone is coming up behind you faster, he judges when you will be moving to the right and tries not to slow. This means he may get pretty close. Move over quickly, more quickly than in the US. You may feel you are cutting off the car you just overtook, but they expect it.
The Garmin had us exit near Sienna. We headed toward Sienna on a main road whose speed limit is 110km/hr. Again, stay in the right lane as much as possible and you'll be fine.
We finally headed north on a small road towards Greve. Speeds are clearly marked. Most of the time it was 70km/hr, but the gorgeous road was so twisty I rarely drove that fast. In very curvy stretches the speed drops to 50km/hr. In small villages it might drop to 40 or even 30km/hr. Look for signs, they are well marked.
I was overtaken by locals every once in a while. I looked for the nearest turnoff and let them by. They waved in appreciation.
To sum up, if you are a confident, safe and defensive driver, you should have no trouble driving in Tuscany. Tommorrow we take the bus to Florence to stay out of rush hour traffic and trying to find parking.