The apartment ist neat and tidy, in an area close to the harbour and the main train station. The airport bus stop (alibus) is only 10min away and the bus comes every half hour. But Taxi is cheaper if you are four people ^^
You'll find everything you need in the apartment, except cooking ingredients like oil and salt or laundry detergent. But there are two grocerie shops within 50m radius.
If you visit naples, don't miss Peompeji, the Vesuv and especially Capri = )