Modern, fast Eurostar trains connect Florence with Italy's main cities, and local trains from other parts of Italy and express trains from around Europe arrive in Florence. The main station is Firenze Santa Maria Novella , on the edge of the historic old town. Other small stations are Firenze Campo Marte (near Florence Stadium) and Firenze Rifredi. If you take an Intercity train to Florence, you may need to change at Rifredi for another train to Firenze S.M.N. The transfer between stations via train is usually already covered by your train ticket (to check for this, your train ticket should not differentiate between the Florence train stations and will simply say "Firenze"). If you happen to have a long wait for the transferring train, it is also possible to take a bus to the city centre, but this is probably not covered by your train ticket.
By 2009 a new station designed by Sir Norman Foster should be in operation for the high-speed train that will connect Naples with Turin, via Rome, Florence, Bologna and Milan. Located in the Belfiore area, it will be linked by tram to Stazione di Santa Maria Novella. The high-speed trains (Treni ad Alta Velocitŕ, or TAV) will pass along 7km of underground track beneath the city.
You might want to consider the overnight train connections to Florence from Paris or most German towns. For example, the train from Florence to Munich leaves at 21:53 and arrives in Munich the next morning at around 08:00. You can sleep comfortably the entire way and it costs about ?100.
The train to Vienna takes about 12 hours and costs ?70.