We've been to Bermuda 5 times - twice cruising, most recently in July on Celebrity. Bermuda is a beautiful island with very friendly people. I know you will enjoy it. When we sailed RCCL a couple of years ago to Bermuda, we docked at the Naval Dockyards for a couple of days and in Hamilton for a couple of days. Do check out the Naval Museum when you're at the Dockyards. The Commissioner's House sits up on a bluff overlooking the sound and contains many interesting exhibits. When you're docked in Hamilton, you're right downtown - you can step off the ship and walk across the street to shops and restaurants. St. Georges is a neat little town at the opposite end of the island from the Naval Dockyards.
You can get a three day bus pass which gives you unlimited rides on the buses as well as the ferries. It was about $25 per person and is the best deal. Taxis are expensive and the scooters dangerous. Be prepared. Bermuda is not cheap! I'd suggest you take all you meals on the ship. We had lunch at a tavern in St. Geroges and two ham sandwiches and iced teas cost almost $35.
That said, however, Bermuda is one of our favorite vacation spots, and the Grandeur is a beautiful ship. You're sure to have a great time!