I deal with this all of the time. When "shipping" with a carrier or courier from the US to Canada, the item that is being shipped will be tariff classified. Some tariff items are free and others the government want a percentage of. I think for a book you won't have to worry about the government slapping any extra fees on to it.
There will be of course Duty and Taxes on the item, plus probably brokerage fees. Other fees may be ACI Release Fees, NAFTA Fees, etc. I remember once having some CD's I bought couriered to me and when I got it I flipped out how much I had to pay.
Now if they are smart ... a book can be "mailed" from the US to Canada and most of these fees are not even applicable and is not a hassle.
"IF I COME ... I'M BRINGING THE PAIN WITH ME"