The first thing I did was join the meet and great thread for my particular cruise on cruise critic. I followed that thread and would find out when people could book things.
It appears RCCL does not open things online at the same time for each cruise, so you have to check often. As soon as I saw something open, I would book it. I ended up booking the major shows, the Ripcord (sky diving simulation) and the Northstar prior to the cruise. We also booked early dining (at the time you had the choice of fixed doning or my time. If you are in my time dining I would suggest you go online prior to the cruise and book a time for each day. It is much easier to change the time when you get on board than trying to get a reservation if you wait.
We were in a suite, so were able to eat in the suite dining room (Coastal Kitchen) 3 meals a day, but we only ate there a few times during the cruise. We also didn't need to reserve the shows, as there was special seating for suite guests. Since we were on a long cruise, the main shows were repeated a few times, so it was easy for everyone to get into them. We enjoyed all of them, and also enjoyed a lot of the varied entertainment all over the ship.
We had no kids with us, but visited the kids clubs and they looked fantastic. The Seaplex area is a great place for tweens and teens. It is huge and has video games along the sides. The main area rotates between bumper cars, soccer, basketball, circus training, and possibly more.
We had no trouble booking the italian specialty restaurant once we got on board. You can see your accpunt and book reservations on your tv in your room.
Denise