1) You need your visa application fee
2) A valid passport
3) If you are accompanied by relatives they need a valid passport too.
4) A passport photo for you and the accompanying relatives with you
5) Visa issuance fee (for some countries)
6) Marriage and birth certificates for your spouse and family
7) Notice of approval of your H-1B petition
8) Form DS-156, Nonimmigrant Visa Application
9) Form DS-157 (to be filled out by males between the ages of 16 and 45)