Ptur, You can do Pompeii and Hurculanium on your own if you like some adventure. You would need to get from the pier in Naples to the train station, which can be done using a local bus or a taxi (you might have to grab a taxi on the street since most inside the port want to only take full-day bookings). You than take the Circumvesuviana Line (their platforms are on the lower level of the station) to Pompeii Scavi and Ercoliano Scavi (both stops are actually on the same train line) where the stops are close to the ruins. When you get to the first ruins (you can do it either order) you want to buy a combination ticket which costs 18 Euros and allows you admission to both Pompeii and Herculanium (this saves you 2 Euros per person over seperate admissions). At the sites you can either pay to join a guided group (usually about 10 Euros per person) or you can rent a self-guided audio-tour. Both of these ruins are wonderful,,,but be prepared for a lot of walking and pray that it is not very hot.