so, the question is: If we fly into Rome, is it easy to get to a train that will get us down to Sorrento? What kind of time frame? Do we have to go to Naples and if so, how do we get to Sorrento? caio
You can get a train from Rome to Naples. In Naples you transfer to a commuter train called the Circumvesuviana which goes by Pompeii on its way to Sorrento. Airport to Rome - 35 to 45 minutes. Rome to Naples - 2 hours. Naples to Sorrento - 1 hour. (All times rough from memory)
There's also a bus directly from the bad Rome train station to Sorrento you can take if you really want to avoid Naples (Google: Marozzi Rome-Sorrento), though the train is easier and enables you to have a nice pit stop for good pizza! :-)