Church near the main train station.
I only had one bad experience in Florence. A man followed me for about a mile or two down the river. He would never get really close to me, but I could tell he was following me. I pulled all the tricks too, sitting down, tying my shoe, taking pictures and yet he persisted. When he finally approached me, nobody was around and he tried to get me to take a "shortcut" through a shady alley. His behavior was really dodgy and he scared me enough to make me nervous, so I latched onto the first Americans I heard. They were from upstate New York and were really nice. They let me walk around with them for about 3 hours.
View from the River.
I can give a few suggestion about visiting Florence. First of all, don't spend your money on the Uffizi gallery. Yes, they have a few Botticelli's, but they are not worth the wait or the money. It was a big disappointment. Second, don't go to Dante's house. It isn't really Dante's house, it is a museum built on the foundation of a building which is "largely believed to be Dante's house." It was boring and just had passages about the time period and nothing much about Dante. Third, and this is the most important, DO NOT buy anything from street vendors. The police can and will fine people 10,000 euros if they catch them purchasing such goods.