Three things learned from personal experience and the experiences of others:
Oniline Check-in:
If you haven't done it already, do it ASAP. http://www.royalcaribbean.com/onlinecheckin
You will need your passport and your e-docs and your credit card.
Which brings me to...
Budgeting:
When you check in at the pier you will get a SeaPass card. This is how you will pay for things on board. BE CAREFUL! This is not a credit card. You will be required to settle up at the end of the cruise. To some people, the itemized accounting of your spending during the cruise can be quite shocking. Depending upon your method of settling you onboard debt, you may want to make sure you have enough room on your credit cards or in your bank account before you leave.
You definitely want to have enough funds available to give your waiter, assistant waiter, headwaiter and room steward...
Tips:
Your eDocs (did you read them yet?) have a section on tipping guidelines. It might be best for you to set this cash aside ahead of time. No, you are not required to tip these four people, BUT they do work hard and don't earn a lot of money. If the people who have been busting their tails to make your cruise a special time by bringing you food or making amusing towel animals for your cabin have done a decent job, please don't forget them at the end of the cruise.
Having said that...
Tips (part 2):
If you get drinks from the bar or from one of the 19,807,219 guys and gals walking around the deck with fruity rum drinks with umbrellas in them, be aware that a 15% tip is already included in the price of that tasty beverage. You will notice there is a line for an additional tip. Use your judgement here, but don't over tip.
