Angela K. Nickerson, author of “A Journey Into Michelangelo’s Rome,” has written a free insider’s travel guide to the locations featured in “Angel & Demons.” Just to make sure you didn’t miss it, I said free. As in all 43 pages of it. “Rome’s Angels & Demons: The Insider’s Guide” offers great back-story to the historical characters that Dan Brown uses in his novel and at the same time offers practical travel information for visitors to Rome who want to see the sights for themselves. Here is a Q&A with Angela as she tells us more about why the book is so handy for travelers and how you can use her book to go on a self-guided tour of Rome, hitting the same locations you saw in the movie.