The Canada Revenue Agency
Ontario Ministry of Revenue
The federal Department of Finance is responsible for the development of federal fiscal policy, including laws affecting federal taxes, financial institutions and markets, and federal-provincial transfer payments.
The Bank of Canada
The Bank of Canada site includes a variety of useful features, including information on interest and exchange rates, financial indicators, securities auctions and more. The convenient "Currency Converter" allows you to determine Canadian dollar equivalents for a broad range of foreign currencies.