We are trying to decide whether to buy train tickets online ahead of time or when we arrive in Italy. I've seen travelers post both ways. Which is best?
By all means, buy them when you're in Italy. It's very easy at the train station.
It's easy to buy all your tickets once you are in Italy. If you do buy your tickets online ahead of time be sure to use http://www.trenitalia.com/en/index.html. The other websites charge a lot more money for the same tickets. But you're safe to buy them in Italy.
I guess the answer is there's no "best way." Buying in advance from Trenitalia may give you discounts that are not available when you get there, and the peace of mind you'll be assured of a seat on trains that require reservations. Purchasing in Italy gives you the flexibility to change your itinerary at a moment's notice.
Buying online through Trenitalia.com might not be an option unless they've finally fixed the severe problems with the system many of us experiencd earlier this year.