Compare the rate in the paper to the rate at the bank or the currency exchange shop. Usually the rate on the website or in the newspaper is better than the rates in the banks or currency exchange shops. Ask about the exchange rate first, and ask about service charges. Banks sometimes make you pay a percentage (%) of the total. Usually a currency exchange shop has good rates, and there are many of them downtown and a few near Concordia on Ste. Catherine Street.
Always ask about the service charge before you change money, and always ask for a receipt.