Do I (or the both of us) need to submit documentation of our relationship up until now? If so, what form would this take?
You'll have to look at the documentation required for an FLR(M) visa - the requirements are slightly different when you switch in the UK compared to when you apply for a spousal visa from the US.
Usually, just the marriage certificate is needed as proof of relationship. Also, you've been living in the same country and have been seeing each other in person on a regular basis, so you won't need to prove regular long-distance contact like fiance and spousal visa applicants would.
The FLR(M) form is here:
http://www.ukba.homeoffice.gov.uk/visas-immigration/partners-families/citizens-settled/spouse-cp/applying-in-uk/My next question is about the application process and the transition from Tier 4 to Spousal. When I submit the online application, do I need to make a biometrics appointment to be done in the UK? Or will my biometrics taken for my student visa (which was done in Sept 2011) also apply to the Spousal visa?
You must re-submit biometrics for every visa you apply for - this is for 2 reasons: 1) so they can confirm that you are the same person who applied for the Tier 4 visa and 2) they need a new photograph for your biometrics residence permit.
You don't apply online when you apply in the UK, at least not in the same way as in the US - you normally just print out the application and fill it out by hand (although I believe there is an interactive form you can fill out online, but only if you will be making an online payment for the visa and I've heard that sometimes the form doesn't work properly).
You have two application options:
1) Apply by post (£561)
- You print out the application and fill it out
- Then you mail the application, along with your documents and payment method to UKBA.
- A couple of weeks later, you will receive a confirmation letter from them
- About a month after that you will receive another letter asking you to book a biometrics appointment
- A month or two after you have submitted your biometrics you should receive your visa/residence permit in the mail
2) Apply in person (£867)
- You make an in-person visa appointment at a PEO (there may be a wait of a few weeks for appointments)
- You print out the application and fill it out
- You collect your documents and take them with you to the appointment (your husband must go with you)
- You will pay for the visa and have biometrics taken on the day
- The visa decision will be made on the day and you will receive your biometrics residence permit about a week later in the mail
Finally, since I am already here on a student visa, is there any reason or step in the visa application process that I should have to complete back in the US?
Nope, everything is done in the UK.
See:
http://www.ukba.homeoffice.gov.uk/visas-immigration/partners-families/citizens-settled/spouse-cp/applying-in-uk/