Finance:

Globe & Mail
National Post
Canada Revenue Agency, Tax information and SIN cards  
Human Resources Canada  
Investor Education
Investor Information

General Interest:

Looking to buy or sell? Meet Martin Stothard ~ Click here for a great real estate experience ~
Robb Report
MLS Canada 
Canadian Wines 
Epicurious (cooking)

Investment Information:

Big Charts ~ Chart various stocks and indices
Globefund ~ Tracks performance of Canadian mutual funds
The Toronto Stock Exchange ~Quotes, Charts etc.
Standard & Poor's ~ Standard and Poors rating agency and research