How to ship things from Japan to Canada?

HI,
I'm going to be finishing up my exchange trip here in a Japan in about a month and I was wonder how to send some things (manga, souvenirs and some clothes mostly) back to Canada. I will probably have around 30-40 pounds of stuff and was hoping to send it by ship. Time is not really a huge factor, but cost kinda is(no point paying more for shipping then I did for all of the stuff being shipped). Therefore my questions are
-What is the best way (company, post office ect.)to send by boat?
-On average how much will it cost(a rough guess would be fine)?
-Finally, what can I say at the post office(or wherever) when I'm going to get it sent from?
Any help is greatly appreciated
Arigatou
Mike

The best thing to do is to go to the post office with the approximate weight in kilograms. Send it by EMS is twice the price as SAL. You can send it by surface for the cheapest rates, but depending on where you are in Canada, it could take a couple of months to reach you. Also, make sure to have a detailed list and value of what is in the box, as Japan Post is very particular about it.