With ours we both went in and confirmed date/time etc. Then they make one of you leave the room whilst they ask the remaining one questions about you both (ie, date of births, occupations etc). Then you swap and the other gets asked the same questions to make sure the answers match. That's to make sure you do really know each other and it's not a scam marriage. Then that's pretty much it. They put up your notice in their public board for two weeks and assuming no-one objects then you're all set
xx