Keys of Florence sets you up right at the beginning. After booking, they will send you all the info you need to know as far as how to reach the office, and then how to reach the apartment from the office.
The office and apartment are located conveniently next to the Firenze S.M train station (about 10 mins to the office, and 25 mins to the apartment).
On your way to the apartment, you will pass by the Duomo and the Plaza de Santa Nuovo which also means a bunch of restaurants and grocery stores as well. The apartment is very spacious and clean. We did have some trouble working the air conditioner machine but found it to just work very slowly. There is a WiFi router in the room, but we too has trouble hooking up to it.