Most nonprofits are heavily influenced by a variety of  policies, programs and laws put in place by federal, provincial or municipal governments. They constrain their actions and often provide vital funds. If you are in this group, you would of course like to influence these bodies to develop their policies and laws in ways that support your mission. But you can't influence anything if you don't know how it works. These sites provide a great introduction to the way governments operate in Canada and how to engage in effective (but legal) advocacy activities.