My appointment was June 18th @ 11:30am. I arrived at 11:15am and showed my DS160 and passport and they sent me through to security which is the same as in an airport. Then you exit through some (extremely heavy) doors and this is where you are meant to find the queues. However they were none existent and i was the only person there! However there are two lanes on the right and one on the left which is specifically for US Citizen Services so when there are queues you can use this left lane to skip it. Once through you will take the elevator to level one. Then left out of the elevator and follow it left around the corner to a smaller waiting area and wait for your number to be called. It took about 40 minutes for my number to be called and I was asked for the following documents: DS160, Passport, Confirmation of payment for the interview, birth certificate, 1 x US passport pic, affidavit of support and letter of employment. I had tons of additional evidence and nothing else was asked for (not even W2s) but far better to have too much than not enough. I was then given my chest X-ray back from my medical and told to sit back down and wait again until my number was called.