Here is what you need to know about Naples before you go:
1: Maradonna is a God to the people of this city. Their home football team has never been so victorious and glorious as it was in its Diego M. heyday.
2: Mozzarella should come from buffalos. NOT cows. Taste the difference and you'll never go back to that chewy, rubbery cow stuff.
3: Naples is a good starting point for travelling to Pompeii, Sorrento, the Almalfi Coast and the islands. Just take the Circumvesuviana trains, from the main train station. It's super cheap (about 2 dollars to Pompeii) and easy.
4: Neapolitan culture is alive and well. Tourists must not expect the same kind of Americanization that is so predominant in the north of the country. There is no Disney shop. Few people speak English. Traffic laws are generally ignored. Signs are in Italian. Napolitans do things their way, which they generally regard as the best way and are very proud of it. Bless them!
5: Naples is relatively poor, but it is not cheap.
6: Violent crime is rare, but petty theft is not. Watch yourself and your belongings. Be alert at all times, not just for theft, but for rebellious scooter drivers on the sidewalks.
7: Naples is rich in history. Brush up on it before you go to make your stay all the richer.