Legal research and writing has its own citation style. Your best source for Canadian legal citation is the Canadian Guide to Uniform Legal Citation (call number: KE 259 .C36 2010), also called the "McGill Guide". You may also want to have a look at the online guide to Legal Citation maintained by the Lederman Law Library at Queen's University.
If you are using a particular citation style (e.g., MLA, APA, etc.), the style guides will provide guidelines for citing legal sources. Writing and Learning Services has developed an APA Legal Citation guide.