Originally Posted by BritishGav

The guide I used lists these:

1. Payment
2. Cover Letter - signed and dated, maybe a table of contents and say what you're petitioning for
3. I-129F itself
4. Declaration of how you met in person in the last two years. Make sure to sign and date it.
5. Original statements (from both the US Citizen and foreign fiance) certifying an intent to marry within 90 days of entering the US on a valid K-1.
6. Proof of having met in past two years. Boarding passes and that kind of thing
7. 2x G-325A form, filled out by the US Citizen and another by the benificiary signed and dated, with accompanying passport photographs (US specification size) with full name written on the back
8. Copy of the Birth certificate (front and back) for the US Citizen
9. Copy of any final Divorce Decree(s) or Certificate(s) if either of you has been married before
10. Proof of Legal Name Change if applicable
11. If relevant provide certified copies of all court and police records showing the charges and dispositions for any specified conviction(s)

Hope that helps