If doing a consular visa application, then you'll need to send the Affidavit of Support to the National Visa Center in Portsmouth, NH
If, on the other hand, filing for AOS in the States, then you mail everything, including the Affidavit of Support to the USCIS "National Benefits Center" loickbox.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
If you are just filing, follow the form instructions. If you are at the NVC stage, then follow their instructions.
You should retain an experienced immigration lawyer, whether myself or one of my colleagues, to review all the facts, advise you, and handle the case.
J Charles Ferrari
Eng & Nishimura
The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship.
Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.