Clues for a scavenger hunt? That's a tough one. A pretty bow and a picture of a stern face for the Bow and the Stern? A glass of Port...oh wait, these are kids...
I surprised DW for her 12/23 birthday one year, the 7 nt. cruise was embarking 1/11 (she is not the type for whom I would have dared pack, even w/ the assistance of her sister and best friend...gotta know your audience). Wrote a poem, decorated the printout w/ disney clipart, and then presented her w/ a decorated 3 ring binder filled w/ color printouts of the menus, the navigators for our itinerary, all sorts of info, the doc's had arrived and were tossed in there...
For this winter, DS does not know about the 1/2 cruise we have on RCCL, and not gonna tell him. Going to get him out of the house on 1/1, go watch the early bowls somewhere--anywhere--else, while DW packs, including for him. I can pack for myself in advance (something DW will never learn, I fear) while he is asleep one evening and stash that luggage , and then sneak the bags into the car, and when it is time to leave for the airport, just say "come on, get in" and then say nothing until we arrive at the airport, then say nothing until we get to the gate and he sees its to miami, then get to the hotel that night and act as if it is a trip to miami. then wake up, have breakfast on the 2nd, distract him while we check out, then get in a short cab ride and he'll know its a cruise when I tell the cabbie where we're going.
Oh--Wait--no bowls on the 1st--when 1st is on a sunday, bowls are on the 2nd, and the NFL plays on the 1st. I think there are still parades, though. Well, I'll distract him on the 1st somehow.
For your little ones, go to the Disney w/ kids forum, and there are disney crosswords and word finds, things like that. Maybe make your own word find on the computer that will include all the hint words for the cruise?