The Sorrento tourist office is at Via L. de Maio 35, inside the Circolo dei Forestieri club, just down from Piazza S. Antonio.
Also handy—particulalrly for events—is the city's civic site, Comune.sorrento.na.it.
Handles the inline presence for major archaolgical areas, monumenets, and museums in:
Visitor information for Italy
Tourist information, guidebooks, maps, tips for niche groups (students, LGBT, seniors, disabled, etc.), and more in Italy
inside the Circolo dei Forestieri club, just down from Piazza S. Antonio
"Airplane travel is nature’s way of making you look like your passport photo."
— Al Gore