As a canadian, do I need to fill in form W-8BEN to distribute apps throughout the US?

I'm a new 19 yo developer and I've been in the process of filling in contracts and forms for a while. It's getting quite complicated and nothing is really clear. I want to know if -as a Canadian developer- I need to fill in form W-8BEN and send it to apple in order to have my apps sold in the US? What does this form even imply? I know that on iTunes connect I requested the contract to be able to have iAds on my apps, and had to fill in a "US tax form" in which they asked me if I was a resident of the US and other similar questions. I'll be honest and say that I am really confused as to what I need to do. I'd really appreciate if someone that has already been trough this or that knows what I have to do would help me. Thanks in advance!