I'm going to assume you've never been on a cruise ship before... (if you have, then you probably know most of this anyway)
I was on the Carnival Conquest out of New Orleans before Katrina, and going on the Holland America Westerdam in January...
One thing, all inclusive doesn't usually include drinks on a cruise ship. All the food you can shove in your face, but they'll still charge you for beer.
Some may be different i'm sure, but expect booze not to be included unless otherwise stated.
Find the pizza stand quick, it will become your best friend. I must have ate 500 slices of pizza on my trip.
Go for the late dinner IMO (if you have a choice) We went for the early one, and missed every good sunset. Plus, if you're feeling a little peckish, there is always the pizza bar.
I don't know where you're going... so I can't help there...
Lots of fun things to do aboard, me and the GF played bingo every day for fun prizes, they had game shows that we went and participated in, ice carving contests in the middle of the caribbean...
The hot tubs and swimming pools are salt water... didn't expect that. (In hindsight, it makes sense, but still)
I'm really looking forward to my trip, as in less than 1 month, i'll be in the caribbean doing the eastern (Bahamas, St. Maarten, Turks & Caicos, and the British Virgin Islands), as I have done the western caribbean (Grand Cayman, Jamaica, Mexico).
Lots of bars on board with all sorts of different themes for whatever you are into (martinnis [sp, i know], sports lounge).
Internet is deadly expensive, but i'll pay the price to check up on the flames
Thats about all I can muster out of the ol' memory box about taking a cruise.
Oh yeah, don't worry about sea-sickness. They have fancy stabalizers (sp.. i know.. im tired) that prevent the ship from swaying.
If you have a history, take some of those things to put behind your ears just incase.
Google the hell out of it for reviews, more to just get you pumped up for the trip.
http://www.cruisecritic.com/reviews/....cfm?ShipID=15
http://cruiseclues.com
http://www.cruisereviews.com/Celebrity/Century63.htm