traveling from Rome to Sorrento

Best is a subjective term but I would take the high speed train from Rome termini to Naples centrale. From there go downstairs and get on the commuter train, the circumvesuviana, to Sorrento. It's about an hour from Rome to Naples and another hour to Sorrento.

Donna

I agree with Donna and will add an alternative - take the train from Rome to Naples and then take a taxi to the waterfront and take a hydrofoil across the bay of Naples. It's a pretty cool trip and the views from the water are special! You will land at Sorrento and can walk up to the town or maybe even take a taxi to your hotel.

I'd skip the hydrofoil in March, probably. Besides, it's a steep climb up from the sea to the center of Sorrento, and with luggage . . . Taxis are very expensive in Sorrento, partly because of the one-way street system. Take the Circumvesuviana. Most of the town is downhill from the train station.