Instead of this improvised solution, get a small group together - even if it's only 3 or 4 people - and hire a real tour guide in Palermo or elsewhere in Sicily. These college-educated professionals speak at least three languages and are highly qualified to do what they do. Some are actually published historians or archaeologists. They are authorized to accompany you around the city and to lecture at historical sites (in churches and museums, for example). Check out our Sicily tour guide page for listings. This requires some foresight, but why leave your visit to chance?
And for realistic, reliable information on transportation and sightseeing in Palermo, check out See Palermo's sightseeing page.