Inquisitor

This is straight from the VJ guide, Id follow it to a T. See number 6.
What to send to your fiance(e) once the I-129F is approved (Receive NOA2):
1. A copy of the entire I-129f package (that you made when you sent the petition in) and a copy of information that you sent back due to an RFE (if you received one). Your fiance(e) should review this information in advance of the interview (the embassy will have copies of this as well). 2. Send copies of the documentary proof that you submitted with the I-129F for your fiance(e) to have on hand for their interview at the embassy. Your fiance(e) should review this information in advance of the interview (the embassy will have copies of this as well). 3. Send an original letter affirming your desire to marry your fiance(e) and your continued support of the K-1 Visa. Sign and date the form. This will be similar to the letter you provided with the I-129F, but dated much closer to the interview (it will have most likely been several months since you submitted your I-129F). 4. I-134 Affidavit of Support form. Ensure it is signed, with all required supporting evidence. Begin collecting the required information ahead of time, as it can often take several weeks to collect it all. 5. You will need several items (for the above form). Gather duplicate evidence of income and resources as appropriate:

(A) Statement from an officer of the bank/financial institution with your deposits, identifying the following: 1. date account opened; 2. total amount deposited for the past year; 3. present balance
(B) Statement(s) from your employer on business stationary showing: 1. Date and nature of employment; 2. salary paid; 3. whether position is temporary or permanent (also include copies of your last two pay stubs and your previous W-2 for the associated employer if available)
© If Self Employed: 1. Copy of last income tax return filed (or IRS transcripts); or 2. report of commercial rating concern
(D) List containing serial numbers and denominations of bonds and name of record owner(s).

Begin collecting these ASAP after your NOA2 arrives. See this FAQ for more tips and useful information on the Affidavit of Support Form. 6. A copy of the NOA2 that you received in the mail. (backup information; the embassy will have copies of this as well) 7. Proof of your ongoing relationship. This needs to be taken to the interview! Include photos, travel documents, emails, online chat logs (pick several over the prior few months), etc.. from between the time you filed and present (NOA1 until date-now).

Examples: Copies of land line and cell phone bills, appropriate emails and letters you have sent including the stamps on envelopes (to document the date they were sent), and other written documentary proof. Provide a reasonable amount; two to four of each type. Pick a range of dates up to and including the present. You can also include a copy of engagement ring receipt (this is something that is a big optional - do not worry if you do not have a ring yet!)

This is straight from the VJ guide, Id follow it to a T. See number 6.
What to send to your fiance(e) once the I-129F is approved (Receive NOA2):
1. A copy of the entire I-129f package (that you made when you sent the petition in) and a copy of information that you sent back due to an RFE (if you received one). Your fiance(e) should review this information in advance of the interview (the embassy will have copies of this as well). 2. Send copies of the documentary proof that you submitted with the I-129F for your fiance(e) to have on hand for their interview at the embassy. Your fiance(e) should review this information in advance of the interview (the embassy will have copies of this as well). 3. Send an original letter affirming your desire to marry your fiance(e) and your continued support of the K-1 Visa. Sign and date the form. This will be similar to the letter you provided with the I-129F, but dated much closer to the interview (it will have most likely been several months since you submitted your I-129F). 4. I-134 Affidavit of Support form. Ensure it is signed, with all required supporting evidence. Begin collecting the required information ahead of time, as it can often take several weeks to collect it all. 5. You will need several items (for the above form). Gather duplicate evidence of income and resources as appropriate:

(A) Statement from an officer of the bank/financial institution with your deposits, identifying the following: 1. date account opened; 2. total amount deposited for the past year; 3. present balance
(B) Statement(s) from your employer on business stationary showing: 1. Date and nature of employment; 2. salary paid; 3. whether position is temporary or permanent (also include copies of your last two pay stubs and your previous W-2 for the associated employer if available)
© If Self Employed: 1. Copy of last income tax return filed (or IRS transcripts); or 2. report of commercial rating concern
(D) List containing serial numbers and denominations of bonds and name of record owner(s).

Begin collecting these ASAP after your NOA2 arrives. See this FAQ for more tips and useful information on the Affidavit of Support Form. 6. A copy of the NOA2 that you received in the mail. (backup information; the embassy will have copies of this as well) 7. Proof of your ongoing relationship. This needs to be taken to the interview! Include photos, travel documents, emails, online chat logs (pick several over the prior few months), etc.. from between the time you filed and present (NOA1 until date-now).

Examples: Copies of land line and cell phone bills, appropriate emails and letters you have sent including the stamps on envelopes (to document the date they were sent), and other written documentary proof. Provide a reasonable amount; two to four of each type. Pick a range of dates up to and including the present. You can also include a copy of engagement ring receipt (this is something that is a big optional - do not worry if you do not have a ring yet!)