Packing
What you should pack
It is advised to pack light so that you may bring home souvenirs, but there are few items that we need, so just bring an extra empty bag. First, every cruise has a least one formal night. If it is more than three days there will be two or more formal nights, so you will need to pack a suit jacket and trousers or evening gown. Other “must haves” are: Swim suit, Work out clothes, Comfortable walking shoes, Sunscreen, Prepaid calling cards (some phones lines do not work everywhere), Cash for tips ( two dollar bills and five dollar bills are good to get in advance), Camera and a bag that is separate from your luggage to carry on with as you board. You will need this bag for your documents, change of clothing and medication. After boarding you will have to wait for luggage to arrive at your room before having access to them.

What you should not pack
What not to pack: Flammable Liquids, Electrical transformers, coffeemakers, candles, iron, and valuable jewelry.

Vacations At Sea
Taking a cruise is like having two to three vacations all in one. While on a cruise you get to do many different things and go to many different places all on one cruise. There are tons of activities (depending on your cruise) such as: swimming, shopping, rock wall climbing, visiting the spa, bingo, playing at the casino and much more. What will be included in your cruise will depend on the cruise line that you use, but for many cruises meals, lodging and activities are included in the price.
Documentation
Passport or no passport? It is best to carry a passport but you will have to check with your cruise line to find out other documentations that may be needed. Non US citizens will need a passport and visa or alien registration card, US citizens will need a passport or State issued ID for domestic cruises. It is a good idea to have copies of all documentations at home with a responsible person or in a safe place where a responsible person could access it if you need your documents sent to you while on vacation. New Passport Requirements
Luggage OnLine