Here is a website I've found useful when shipping to Canada. It allows you to see how much the extra fees will be once the piece gets to the customer. This is nice if you want to combine some of the fees together with the shipping costs and pay for that when you're buying your shipping label, or if you want to give the customer a heads-up on your product information. I was shocked when I saw how much the brokerage fees were and I was flattered people liked my stuff enough to spend that much extra to have it :)
Check it out!