We are traveling three times in a 10-day period. My sense is that we don't need a railpass, but I think reservations make sense. How do we go about doing that? And does getting a reservation mean we've also bought tickets?
We struggled with this decision on our first trip to Italy in May 2008. Our itinerary was Rome, Assisi, Florence and then back to Rome - all by train. While planning the trip, I referred quite a bit the Trenitalia website for scheduling and also thought a lot about buying tickets ahead of time. In the end I didn't purchase the tickets ahead of time and had absolutely no problem whatsoever getting train tickets for every train we needed. The reason I decided not to buy ahead was that I wanted flexibility in our schedule. What if we weren't ready to depart at the time we reserved? What if we wanted to leave earlier? Italy has train travel mastered and I encourage you to leave this aspect of your trip flexible. One thing I did do though, is that I printed the train schedules for the general times that we wanted including several options and brought them with me. This helped us decide our travel times and it helped when I arrived at the station to buy tickets - even though I speak very basic Italian I wanted to be sure the agent and I could communicate. Have a great trip!
For train travel solely within Italy, point-to-point tickets are almost always cheaper than a railpass.
For trains that require seat reservations, the reservation comes with the ticket. No reservations are possible on regional trains.