How tor reach Arezzo and Stia (Florence)

Hi,
I will be travelling to Florence this week. From there I have to reach Arezzo and Stia. I suspect that my driving licence will not be accepted in Italy so I would really appreciate if someone explain me how to reach these areas by other means of transport. And also I would be happy to hear about sightseeing destinations around Florence, Arezzo and Stia (yea its possible to check them from wikitravel website but it's always good to hear from local members...)
Cheers