• Passport
• Two drafts (for \$75 and $45, check here for latest update)
• Offer letter (copy of which is filed along with your docs, at INS)
• H-1B approval form (I-797, looks in a different color, sent by your future employer)
• LCA (Labor Condition Application, sent by your future employer)
• Form I-129 (sent by your future employer)
• Original degree certificate.
• Original degree marks memos
• Original diploma certificate with all the marks memos, if there is any
• Current and past employment/service/experience certificates
• All hike letters, etc from the current employer
• Other certifications (they'll never ask you for these)
• One passport size photo (preferrably two)
• Stapler and/or gum

They may ask you for the following also:

• Identity card of present job/employment
• Business (visiting) cards
• 2 copies of resume
• S.S.C. and 10+2 certificates

NOTE: Check the info in the visa stamped like (passport number, full name, consultant name, etc)