Things Americans in Naples like...but shouldn't:
Eyewitness Travel Guides
These gorgeous guidebooks are great for leafing through to get inspired about where to go...but then are next to useless when you get there. Their glossy pages are too heavy to carry around, and they only list the most touristy/expensive hotels and restaurants. Yes, some of the maps are nice, but usually you can get even better ones for free at the tourist bureau.
For better options, see the Naples Area, Italy, and Europe travel/sightseeing sections of Wikinapoli, especially the section on Europe travel books. Bottom line: for carry-around guidebooks to major sights or information on accommodations and restaurants that locals might frequent, stick to this website, Rick Steves, Time Out, and other guidebooks.
The Margherita pizza was supposedly invented at this pizzeria, a stone's throw away from Piazza del Plebiscito. However, its pizzas are half as good (and twice as expensive) as those from several great Centro Storico pizzerias (da Michele, Sorbillo, Matteo, Presidente...). If you ask Neapolitans what their favorite pizzeria is, odds are they won't say "Brandi." For better options, see the Wikinapoli Pizza Page, as well as the Naples Restaurant and Naples Downtown Restaurant listings. Bottom line: the Centro Storico can't be beat when it comes to Naples pizza (well, except maybe for La Notizia in Vomero).