Florence to Siena

It's covered well in Rick's books. Basically, make sure you take the rapido corso bus, not the regular bus, and not the train. The bus station is around the far side of the train station: looking at the station from Santa Maria Novella, it's around on the left side. You can get the times at the station, but be careful: they will forget to tell you that on some weekend days and holidays only certain times run.

Thank you

John,
See http://www.sitabus.it/sita-toscana/Firenze-Siena2010.pdf

Take the blue SITA bus, the website in the posting above will show you the bus schedules. Buses run very regularly throughout the day, the express bus takes about an hour and a quarter to reach Siena. The bus station is practically next to the main Florence train station, Santa Maria Novella - to the right if you stand outside the building. You'll be wanting the regional bus station ("pullman") not the regular local bus station ("autobus").