documents
I had carried all the papers I can think of
a) Tax Filings for the past years
b) Lease Document
c) Automobile papers
d) Insurance Papers
e) Bank Statements
f) Utility & Phone Bills
g) Spouse Joint A/C Bank Statements ..etc
h) Marriage Certificate, DOB for you, spouse, Children
Most importantly
i) All your GC paperwork
j) Last 6 paystubs
k) Recent Employment Letter (It is good to have the same job title as your labour Cert)
l) Your Passport/s with I-94
m) Interview Letter
n) EAD
o) Advance Parole
I had bought a file and arranged all my paperwork with proper labelling. It always helps when you furnish the paper quickly when asked for.
My suggestion is please be simple and precise while answering any questions.
Hope this helps