Use a CREDIT card; not a DEBIT card. Far fewer difficulties for international charges. Pay it off every month just like real money.
IMHO all debit cards are a scam by the banks to put a hold on your money and a target for crooks to drain your account.
All of that rant does assume that your credit rating is good enough to get a no-annual-fee card and pay the entire balance each month. Get a Discover Card or a Bank of America rewards card and the rebate percentage will more than pay the transaction fees for charges in Canada.