Which terminal do we use out of Rome into Florence? If we decided to go to the hill towns first from Rome before we went to Florence would we still take the train? If so which hill town is the easiest to get to for a few days prior to Florence?
Orvieto would be a good choice. It is just over an hour from Rome and 2 hours from Florence.
The train station in Rome depends on the train company you use. Most of the trains to Florence are operated out of Termini by Trenitalia about 50/day. The newer Italo trains, and less frequent, operate out of Tiburtina which can be reached via subway from Termini.
Is termini the easier one to get in and out of? That's the main priority, less trouble
Dale, Yes, Stazione Roma Termini is the easiest station to use as it's very easily accessible. If you're going directly to Florence, your destination will be Firenze Santa Maria Novella (often abbreviated as "SMN"). The trip on the Freccia high speed trains is VERY easy and quick. Note that reservations are compulsory, which will be included with your tickets. Which "hill towns" are you planning to visit? You could perhaps get settled in Florence and then visit a few hill towns as day trips from there. Orvieto (which is in Umbria) is only about an hour north of Rome so you could stop there for a few hours on the way to Florence. The only issue might be luggage storage, as there's none at the station. However, the Guidebook mentions a local hotel that will store luggage for a small fee (I can't remember the details). Happy travels!
Trenitalia has 55 high-speed trains from Rome to Florence each day. Most are non-stops so they just whiz by Orvieto. Trip takes 1hr35min). If you wish to visit Orvieto, it's a 1-hr day trip from Rome. Or, if you wish to visit on the way to Florence, you will be on a slower Regionale train to Orvieto (1hr). From Orvieto to Florence, you give up the choice of fast trains and you will be on Regionale or intercity trains from Orvieto to Florence (2.5hrs).