Hi curmar1,
Welcome and congrats on your upcoming anniversary. We sailed on the Explorer of the Seas last year, and it's a great ship. Try to get on as early as possible, because the moment you get on board is when the cruise actually starts. As soon as you get on board, drop off your bags and tour the ship to get a flavor of what you're in store for. Go up to the Windjammer Cafe to get some lunch before the crowds, then find a drink and wait for the muster drill. As soon as thats over, join the sailaway party on the top decks, and watch the land disappear over the horizon. Always a magical time.
There are a few things that you shouldn't miss on the EOS. First of all, make sure that you get tickets for the ice show (they're free). It realyy is good, and very unique. Also, RCCL has an adult scavenger hunt called The Quest which you shouldn't miss.
This may be your first cruise, but I'm willing to bet that it will not be your last. Enjoy. :grin: