Well being a soon to be "newbie" myself (my trip is coming up June 1st)....I have heard to either wear (for the ladies I'm going to say under your sundress, etc) your bathing suit onto the plane. I have heard from several of my friends that if you arrive at your resort early your room may NOT be ready!! Apparently check in at several of the resorts is not until 3pm so if you arrive prior to that you basically have nothing to do so it would be wise to either take your swim wear in your carry on so that you can just go directly to the pool bar
until your room is ready. I have also heard that if you like to lay out on a float you should buy a cheap one and pack it in your luggage because apparently they are hard to find and very expensive.
Hope this helps a little?!?!!