We have gotten the usual stuff so we can prove our marraige is credible.

1. Her last name changed
2. Joint checkings and savings accounts
3. Health Insurance together
4. Me being a benefactor on her Life insurance
5. A joint Credit card
6. about 15-20 pictures
7. letters from our families saying that they have have met us and how long we have known each other before marraige.

What else would help us and we should take to the interview?

THe following items might be of help:
1.title of house or lease contract showing join tenancy.
2.utility bills showing,mr.& mrs.
3.mails showing mr.& mrs.
4.car registration,birth
5.birth certificate of child born of marriage showing names of parents
6.letter of employment showing the name of person to contact in case of emergency
7.current will showing one spouse as beneficiary

Remember, you just have to prepare these and not guarantee of anything.Best of luck.