You have to carry the following documents for the H4 visa interview. You have to split the documents as two types one as Mandatory documents and the other as Supporting documents. So you will keep the Mandatory documents in one cover and the supporting documents as another cover. It will help and easy to find the documents at the time of interview.
1. Current passport and old passports
2. DS-160 Confirmation page
3. Original interview appointment letter
4. I-797 photo copy (Original not required)
1. Photocopies of the passport (all pages)
2. Original Marriage certificate
3. Original birth certificate
4. Photocopy of the principal applicants valid visa page.
5. Wedding invitation card.
6. Marriage ceremony photos (Carry min 10 copies)
7. Pay stubs from principal applicant's current place of work and income tax return.
8. Principal applicant's all passport pages photocopy.
Remember your passport number.