If you're using
Disney Cruise Lines then you'll be able to book transportation on their busses from the port to any WDW resort. You can do this prior to cruise by contaction
DCL or your
travel agent. Also, you can book this transportion while on your cruise. Its a simple process - you get off the ship, retrieve your baggage or have a porter assist you, go through immigration/customs, once outise you go to the counter and they'll direct you to whichever bus will be going to your resort.
I'm not sure what the cost is right now as it may have changed from when we cruised on DCL last.