The online booking process works well. I have used it twice. The information that you complete on the booking screen is transfered to the cruise documents when they are printed.
I just booked a 2-night cruise to nowhere on the Millenium which sails on October 25, and I booked the cruise around October 4. After booking the Cruise I completed the information screens. I received my cruise documents around October 11 and the information that I had entered was printed on the documents.
Use the process. It works well, and don't forget to register for a Cruise Critic party (different screen).