Heres what you do :
Send your I-130, G-325As (one set for you and one for your hubby), your photos, and photocopies of the rest of your supporting evidence in an envelope to :
DHS (Immigration) / I-130
American Embassy
PO Box 2444
London W1A 5WT
And
Send your hubby's DS-230 Pt I (and ONLY part I) in a seperate envelope to :
Immigrant Visa Unit
American Embassy
5 Upper Grosvenor Street
London W1A 2JB
Dont send DS-230 Pt II as you'll need it for the interview. Fill it out but DONT sign it because that needs to be done in front of the immigration officer.
You can include the DS-2001 Checklist if you have all or most of your interview evidence assembled or you think you can get a hold of whatever's left within 30 days. Dont submit the checklist if you dont have at least 90% of what they need already on hand.
If you still have to work on gathering evidence for the interview you can submit the checklist at a later date to the same address.
You can keep up to date and verify those addresses by going here:
http://www.usembassy.org.uk/cons_web/ins/insindex.htmIts the most important web site during this entire process and if you look carefully you'll find mostly all of the answers you will ever need. You can also contact the embassy direct though email rather than having to call. The people doing the email answers are very prompt, usually you get replies in a couple of hours.
Notes on the G-325As: use the adobe pdf to fill the forms out on your computer if you havent done so already. All you have to do is fill out the first page and it'll auto fill in the rest of the 3 pages for you - theyre identical. Just check the 3 remaining pages to make sure theyre correct before printing.
I checked the "other" box and wrote I-130 next to it on every page. The other two boxes arent correct for your situation.
During the interview I dont seem to recall having to submit anything that they didnt ask for specifically. I took a lot of different kinds of evidence with me to cover anything they might have requested but out of our own experience and all the experiences Ive read of others - they really only request what they asked for to begin with and some times dont even ask for bits of it anyhow.
Never hurts to be prepared but for the most part they have to go through so many interviews in a day that they just dont have time to muck about with anything other than what's laid out in the instructions.
Hope that helps,
Sarah