We were in Rome last December and did several tours including the Sistine Chapel and Vatican. A tour is the best way for these. Tour guides there must be licensed and pass tests - they are very knowledgeable and you learn so much. Go online and you can purchase the tickets ahead of time - just google tours in Rome. Tell them where your ship docks and they will arrange transportation or tell you how to get to the starting place of the tour. We were in Rome 7 days and did many of them. Have a wonderful trip.