In my wife's case;

Copy of I797 worked fine ...
I send following related to Company
Appointment letter,
Employment verification letter,
Pay checks,
Company brochure,
Few photographs of mine taken in company,
All docs submitted while applying H1B (I129, ...)

Question she was asked were:
1) Company Name?
2) Date of marriage?
3) How do we meet?

I was lucky for the first time that she got visa and she is here with me in USA.

Hope this will help,

Feel free to let me know if u have any other question ...