You sign in on the website and check your reservations. If you have a guaranteed cabin, your cabin # won't show. We usually don't know our cabin # until we check in at the dock but sometimes we can call our TA and she can find out a day or two before.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean