Train from Rome to Sorrento help

Others know the details of this better than I do, but I've done it 3 times. I used bahn.de for train schedules, but others might recommend a better site. You take a train to Naples, then go downstairs to the Circumvesuviana (commuter train) that takes you to Sorrento. Others may have better info for you but that's how we've done it. Some people are worried about taking the Circumvesuviana b/c of pickpockets, some are not. We are not. We've ridden it 45 ? times and never had, or saw, any problems. We actually enjoy it because it feels like an authentic, "locals" experience. We love all things Italian, so it was fun for us.

Susan is basically correct. You can buy tickets on-line in advance from Rome to Naples. The only reason to buy in advance is to take advantage of any discount tickets that might be available BUT those tickets are non-change, non-refund so be absolutely certain of your time. You don't need to buy in advance for a seat since it is very rarely for a train to sell out. The Circumvesuviana is a local commuter train and you buy your ticket at the ticket booth prior to boarding. No discounts available.

You roughly have four to five trains an hour ranging from a Frecciarossa to a Regionale with an Intercity now and then. To gauge pricing an Econ ticket on the Intercity for 2 hrs is 20E, the Fast train - 1 hour 7 mins is 30E in Super Econ and the Regional train at two hours, 45 mins is 11E. You choice - go fast, go cheap.

No need to purchase in advance for the Circumvesuviana to Naples. Just buy a ticket at the window. They run often. Here is a link to the schedule. You should buy in advance for Naples to Rome on the high-speed FrecciaRossa. You can save money buying in advance, but you cannot change the tickets without at least a penalty, so be certain you allow enough time between the arrival of the Circumvesuviana and the departure of the FrecciaRossa. You do not have to go far to change trains, but if your Circumvesuviana is canceled or late, there could be a problem. We have taken a Circumvesuviana with at least two other trains scheduled that could work for us, just in case. You can always hang out at the Naples station and have a coffee at Vyta.

The posters above have covered it but to back them up....

What trains do I take to get to Sorrento from Rome?

Trenitalia or Italo from Roma to Napoli Centrale, and local Circumvesuviana from Napoli Centrale/Garibaldi (they're connected) to Sorrento.

Do I transfer in Naples?

Yes: as described above. You can purchase tickets in advance to Naples if you want to try and take advantage of any price breaks which may be available but otherwise you can buy tickets the day of your departure. You don't need to buy advance tickets for the Circumvesuviana.

Roma Termini is most likely the station you'd be leaving from in Rome.

http://www.italotreno.it/en

http://www.trenitalia.com/tcom-en

You should purchase reserved-seat tickets on a fast train from Rome to Naples but will not have assigned seats from Naples to Sorrento so you'll need to validate those (very inexpensive) tickets before boarding, as is common for any local/regionale train without seat/carriage reservations. Here's the current Circumvesuviana schedule (Naples to Sorrento):

http://www.eavsrl.it/web/sites/default/files/eavferro/Napoli%20-%20Sorrento_1.pdf

Another possible alternative to the Circumvesuviana commuter is the Campania Express. This one has run during tourist season the past couple of years but haven't posted schedules for this year yet so it's unsure if it'll be operating. Anyway, it costs a few euros more and has limited runs but makes fewer stops and is more comfortable than the battered commuter.

http://www.napoliunplugged.com/campania-express-tourist-train-to-herculaneum-pompeii-and-sorrento