I took my Marriage certificate last time and probably will this time "just in case" but they acted like I didn't need it when we went through the line.
Passport wise- you don't really need it for the cruise- it is suggeste as a precaution if you need to fly out to meet your ship or fly home from a foriegn port during an emergency. We opte not to get one this time- there are 5 of us- that gets expensive- and everyone in my immediate family will be with us and my parents are both deceased. SO I'm not worried about having to come home on a family emergency. In addition we will only be in a port with an airport for one day- so there is not a huge chance we will need to fly back.
Not sure about the website question.
Carnival Fantasy 6/05
RCCL Sovereign of the Seas 4/07
RCCL Navigator 12/07
RCCL Navigator 11/08
RCCL Liberty 7/4/09