Hi. Relax! You're almost done, you should be celebrating
Here's the link to example interview questions:
http://www.visajourney.com/forums/index.ph...p;page=exampleqI wouldn't worry, they're not gonna deny you now. Just try not to freak out, be honest and give them the details they want on any of the questions. I've heard people say that the interview's often done in a conversational, friendly sort of way, so hopefully it won't be too bad.
You're meant to take your copy of the entire k1 petition your fiance originally sent in. You should have the originals of everything, all the original plane tickets, receipts, etc. Also you're meant to have evidence of your ongoing relationship, so any emails, letters, pictures, trip details, etc. that you have since the time the k1 was filed. And you're supposed to have a letter from your fiance saying he/she still wants to marry you.
Hopefully you have all that already, but you've got a few days to sort it out if you don't.
I don't know what else you're meant to have, you're a lot farther along than I am. Just make sure you read the instructions to everything they've sent you; and just to be safe, why not go ahead and take the originals/copies of everything you can possibly think of?
Also don't know if there are any particular things needed for your particular embassy. But instructions should have told you.
And taxes: they don't need to see any information on how much you make, your tax returns, or anything. But they do want to see financial information from your American fiance. There should be a way he/she can retrieve last year's tax returns and statements, but I don't even think you need to do all of that. I think if your fiance is over the 125% poverty line, then all you need to do is prove that.
Breathe and congratulations!