what documents i need to carry for stamping in canada

[clooudz]

Hi sir i came to united states on B1 for second visit in first visit i left the country in two months this time i changed my status from B1 to F1. Now i would  like to go for stamping in canada what are the required documents i need to carry. while changing my attorney submitting my friend documents as my sponsor. Now i would like to go for stamping in my break which is after three quarters currently i am in second quarter. Can you please suggest that i need to take sponsorship from my parents or from my friend.