I wrote this information for myself and thought I'd share it with everyone, as it contains information I wish I'd had before sailing.
Cruise line: Royal Caribbean
Ship: Navigator of the Seas
We had an interior stateroom with no windows. This was actually great, as there was no light in the morning to wake us up. It was much easier to sleep/stay asleep. Yes, it's small but we're not large people and we kept the room tidy so it was never, ever a problem.
The staff knows what they're doing. There are a lot of people, but if you just ask someone for help, they'll give it to you. Royal Caribbean is terminal 2. Carnival also has its terminal and is boarding at the same time.