Everything you wanted to know about Canadian Honours and Salutes: http://pch.gc.ca/eng/1287067257112/1287067387688

And for etiquette during the playing of O'Canada or God Save the Queen:

Etiquette during the playing of the national anthem

As a matter of respect and tradition, it is proper to stand for the playing of "O Canada" as well as for the anthem of any other nation.

It is traditional for civilian men to take off their hats during the playing of the national anthem. Women as well as children do not remove their hats on such occasions.

There is no law or behaviour governing the playing of the national anthem; it is left to the good citizenship of individuals.
From: http://www.pch.gc.ca/eng/13594023732...9402467746#a11