The European-wide train schedule is on or about June 14. Since your route goes to Italy, the Italians have not finalized their train schedules yet (and they always wait until the last minute to do so). So in a couple of days, get the EC tickets to Milan if you can snag the 22 euro fare. You will have to take it on faith that, when the time comes, there will be fast trains from Milan to Florence every hour. Keep an eye on the Trenitalia site and be ready to buy the connection when it finally comes on sale, perhaps in May sometime. The Arezzo train is a regional, costs only 11.05 (now, there could be a small price increase), and runs frequently enough that you should not have to worry about it. Just remember to validate the ticket prior to boarding. In fact, it may pay to spend an extra half hour in Florence to buy the ticket there. Like I said, it originates in Florence, so you can be waiting on the platform when they spot the train and jump on and get your choice of seats.