The office is on Piazza dei Priori, open daily 10:00-1:00 & 2:00-6:00, with €5 audioguides.
The town's best site is this gate built of massive volcanic stones in the 4th century BC. It's part of the town walls that were 4 miles around, twice as big as it is now.
Great pulpit and altar. Notice how the entrance is through the baptistry, you couldn't enter until you were baptized.
A small 3-room museum of church art. Well explained in English.
Museo Etrusco Guarnacc
One of the best places in Europe for Etruscan art, it is filled top to bottom with it, though there are few English explanations.
This is a 14th century palace filled with great paintings, the highlights are the Annunciation & the Deposition of the Cross.
Built in 10 BC. and has great acoustics, plus a great view, but a just as good view can be found at the city wall promenade for free. The theater can be viewed for free from Via Lungo de Mere.