As Dave stated, in an earlier Cruise Compass I found online, tickets are handed out that first morning of the cruise, when you are at sea.
Not sure what itinerary you're sailing, Eastern or Western.
Here is the link that I found of an earlier cruise compass. If you click on "day 2" of the Western Caribbean schedule, it will download a PDF file of the cruise compass, and right there on the front page towards the bottom. As of last October it looks like the location was on the Promenade.
__________________
2007 - Majesty of the Seas
2009 - Enchantment of the Seas
2010 - Freedom of the Seas