We are going to Monteroni d'Arbia in October for three weeks. This will be our 5th time in two years that we have visited there (after the first visit we fell in love with the people and area). We rent a large villa and have a lot of friends and family joining us. We always drive ourselves but some of the other people joining us would like to make day trips to Rome, Venice and Pisa and would like to take the train or bus from Siena. Any suggestions would be helpful, websites etc. that I can send them to reference would be greatly appreciated. Thank you.

Autobus
Here is a website with a bus schedule :
http://www.italybus.it/
I think the train schedule is at www.trenitalia.it

Paolo