I just put on my application that we met in Portland, Oregon even though we had been corresponding for several months. We didn't actually meet in person until he arrived at the airport in Portland.
I didn't take any pictures of us together or wedding pictures and the interviewing person didn't ask for any. After all, we had the marriage certificate. She did ask me the date we first met even though it was on the application.
For supporting documents I had: marriage certificate, rental lease, bank statements showing regular deposits--his and mine as well as bank balances, a letter from his employer, letters from social security and my teacher's retirement showing my income, passports, and I think that is about it. She didn't ask for anything else.
After she looked at everything she said, "This looks good." Then she told me to come back at 2:00 pm to pick up my visa.