week in italy with 8 adults and 2 young kids?

One challenge that groups of 10 travelers have had in Italy, as reported here in the past, is renting a car, or cars. Some drivers have reported feeling stressed navigating and parking a large, wide van on the narrower (than here) Italian country roads.
Some groups have rented two cars.
I don't know what the solution is but thought I'd mention that this has been a challenge for some in the past as reported here, since it appears you're interested in visiting smaller towns in country areas that may not be well served by trains.

If it were me I would rent a villa with a pool. Keeps the kids happy and cool and the adults have plenty of room. Something near Siena would be central to Tuscany and the roads are not difficult to drive. Many of the villages have lots outside of town and fairly easy transport into them. There is so much to see and do in this area that everyone should be pretty happy! Some friends of ours did something like this not too long ago and found a rental van that could seat everyone. The challenge might be finding appropriate car seats for the kids? Don't know what the law says about this in Italy but, regardless, I would want my kids safely strapped in!

Rent two or three cars. Surprised you'd take on Europe when you haven't done much traveling with the children! (Assuming they're yours) The 2 year old isn't old enough to be reasoned with yet, and he/she will just want to be comfortable. Neither of them will care about the 'sites." If you take the advice of the previous poster and rent a villa (assuming you're going to be there in Summer) that will be the best option, in addition to having at least two cars which you will need even without the kids! Be aware, though, that Europeans don't 'heat' the pool water.

Please, People!! Don't think I dislike kids! I've raised 5. Never did Europe till the youngest was eight. Rented condo's here in the U.S., easier to feed the kids 'on demand.' Two years ago took my 11 year old Granddaughter to Paris, Best Trip Ever, but never would have done it when she was two or five years old.

We did two weeks in Italy this summer with 3 adults, two teenagers and two small kids. Quite a crew.

When planning this out, I quickly discounted staying in a villa or agroturismo as these are remote and would require 2 cars or a van. I decided that a smaller town was best for us, especially one with good rail connections. In the end we chose Lucca, which we had visited previously and knew it had a good family vibe. We rented an apartment and went on 4 exciting day trips during the week we visited. These included Pisa and the Cinque Terre. The kids had a great time biking, eating and playing in Lucca.

I 've had the experience of being part of a large group, who were invited to spend time, at a villa in Tuscany, rented by a friend. Having at least two cars is a plus, despite the added expense. That way you don't all have to agree on outings. Over dinner we'd discuss the proposed plans for the next day; and those without cars would opt to join the ones that appealed to them. Worked very well. With such young kids as part of the group, it seems to me that at least every second or third day should be down time. You should be sure that the same person doesn't constantly get stuck with the child-care. There are scads of houses available to rent. I'd scrutinize carefully, looking for ones with some sort of play equipment. If there's a pool, I'd look for fencing or good separation from the house, so that you don't have to be constantly worrying about danger to the children. A slightly more organized experience than an independent villa rental would be an agriturismo. There are many with whole houses and/or apartments to rent, which are very child-friendly

Jackie,
This may help http://www.slowtrav.com/italy/tuscany/hs_planning.htm

I'm all in agreement with the posters above who said to rent multiple cars and consider a villa with a pool. We've traveled with a toddler in Italy because we found Italy to be exceptionally child-friendly compared to Germany, where we lived. We had a great trip in an apartment in Lucca with a car for day trips into Tuscany and the Cinque Terre. Additional plusses for Italy: lots of pedestrian zones in smaller Italian cities where you can give little kids a bit more freedom to free-range with the pigeons, and Italian restaurants are usually extremely welcoming to children. (Unlike Germany, which I love, but where it is usually easier to get a water bowl for your dog than a high chair for your kiddo!)