Hi Niamh and Colman
Here are some web sites and a little information about the transfers from the airport to the station.
Friends tell us that it is a very easy and a short short journey of less than 7 km. The buses run every 15 mins.
The first web site is:
Naples Airport Guide (NAP)
Public Transport
Road: Bus: ANM buses run to Napoli Centrale railway station, arriving at the port of Naples (Piazza Municipio). Alibus shuttle buses also run to Napoli Centrale railway station and then to Piazza Municipio in the centre of Naples.
Taxi: Taxis are available from outside the Arrivals area.
A second more informative one is:
Trasporti
Ciao
John