If you make train reservations at all in Italy, it's generally something to do a few days, not months, early. Eurostar trains require reservations; on others, it's usually fine to get on without a reservation. You may also want to be sure that no strikes are planned for a day you want to travel; is one resource listing strikes scheduled. You might choose the trains you want to take at . If you want to reserve from home rather than taking time in Italy to do this, I've put together some instructions for doing this on Trenitalia's Italian language site; there's a link to it from my home page with my signature below.

Andrew Missouri