Useful info for your stay in Rome: 

• Book the entrance to the most visited sites in advance, i.e. the Vatican Museums and the entrance to the Colosseum, Forum Romanum, Galleria Borghese, etc. 
• Check the instructions about dress code, or if you need to take your ID to enter specific monuments or areas of Rome (dress code for the Vatican, ID for the Colosseum Underground for example)