Pompeii is one of the most amazing archaeological wonders of the world. It seems that time stops there at the moment the volcano exploded, freezing everything at once in this important town. It is located around 40 minutes from Naples, and it can be perfectly done as a day trip from Rome or Sorrento on the Amalfi cost.
There are are many tours departing daily from Rome, but that is a costly option. The train probably is the best way to get to Pompeii. There are many trains departing Rome, mostly from Termini. Doing a reservation ahead of time usual promises very affordable prices.
The fast trains are an excellent option, it takes only a little more than an hour to get to the main Train Station in Naples -Napoli Centrale- from there one has to jump into a local train. This specific line is called Circumvesuviana. It is a walk inside the main train station of 10 minutes but it is very well marked. It takes 40 minutes from there to get to Pompeii and the ticket costs 3 Euro there is no need to do a reservation.
During high season it can be crowded and one has to be aware of pickpockets. This train runs in both directions every 30 minutes. Once in Pompeii one has to buy the ticket for the archaeological park, it costs 11 Euro, it is open from 8:30 to 5 pm in winter and to 6pm in summer(Admission is allowed until an hour and a half before closing) . At 10 am lines to buy tickets can be very long and at 1 pm there are not long lines. The site is open daily with the exception of New years Day and Christmas.
A good visit takes 2 or 3 hours, this is a vast complex, there are maps and booklets available with explanations, some people may hire a local guide -but it is not something we will highly recommend- those wanting to be immersed even more in the experience may rent an audio guide, but just walking around is wonderful, it is a place that speaks by itself.
It is good to keep track of the time especially to not miss the train back to Rome from Naples.