But you need make an appointment first. I think from setup the appointment to the interview day (get/reject on the same day) will take about 3 weeks, even a month.
Please go to the following link, you can make a reservation for interview online by 10 CAN$, I believe it will be cheaper than telephone reservation. And you can find what you need prepare from this link also. Actually, after you make the reservation, US Embassy will send you a mail to confirm your interview time and all the forms and what you need show during the interview.