That will depend on what you are sending and where in the world you are sending it from, which you have not stated. Your local post office will have the most up to date rates.
Yes, anytime you send something through the post, it will cost.
You send it to an airport that will port the letter to Canada
As of January 2014, it costs $1.15 to mail a regular one-ounce letter from the US to Canada, not including any extra services.
As of 2011 May 30, the rate is $1.75 + tax (About $1.96 - $1.98 depending on province) to send a letter from Canada to Germany. See Canada Post's website for more details.
The cost to send Certified Mail through the USPS is $3.30. This is for up to one ounce. If you want a Return Receipt, it will cost $6.48.
$1.15
Yes.
You need 1 stamp to mail a letter/package throughout Canada
it cost 1.00 to
1.00 Germany
it will cost $8.50