This is for my fellow US sellers. I too was hesitant about shipping across the boarder. First was price then how to do it. I looked at all the carriers and found USPS to be the most reasonable for what I sold. Then I went to these sites and looked at what it was all about.
http://pe.usps.com/text/imm/immidx.htm
http://pe.usps.com/cpim/ftp/manuals/.../Notice123.pdf
http://pe.usps.com/text/dmm300/608.htm
The three links above helped a lot. I hope they can help you if you plan to use USPS.
I will use UPS and Fed for larger items if I can, but only if the customers wishes it.
Good Luck
Greg
Copper Locker