Sorry - just a few more: At the hotel in Venice, there is a garden in the back. It is really very pretty, so go through it and enjoy how pretty it is. Then, you will see a "dock" past it and we enjoyed sitting on that at night and enjoying the water views. We also ate at Pizzeria Vesuvia's in Venice- one of our most memorable meals as the food was great, we ate with several from our group and loved the company, and the service was excellent.
At the Colisseum (sorry, I still cannot spell that correctly), purchase the book that the guide recommends (well, at least our guide recommended it). It basically shows the Roman ruins NOW then has overlays to show what they looked like THEN. Gives you a great perspective on what you're seeing and is a wonderful keepsake.
If you need Wi-Fi, you can purchase an hour or more in Rome, in Artimino it's free, and in Venice you purchase it and it was expensive, or so I thought.