North american credit cards will work just let your bank know you intend to use it in europe. We decided to take some cash which we have already switched to swedish kroner. i am also using debit card to withdraw from atm, no problem, make sure debit card has only 4 digit code. you must withdraw from a chequing acct. not a savings account.
I definitely agree with most of the above. But wow, there are some younger and/or inexperienced travelers on this trip! Ok, well, here's my free travel class, with the caveat that as an American my accounts are with American companies so you Canadians may have some differences.
I'm usually out of the country at least once a year. Mostly Europe, some Asia and Latin America. For the past 8 years or so, I've never felt the need to acquire local currency before arriving. I get off the plane, find the closest ATM in the airport, and take out local currency there. It's never been a problem for me, and ATMs in the country give you the best exchange rates. I would avoid going to those foreign currency counters/stores you'll see in the airports, or bother with exchanging money before you go, unless you just want the peace of mind. It will definitely be more expensive than going to an ATM once you land. As was suggested above, make sure you have a 4-digit PIN and make sure your money is in a checking account.
I try to take out only a bit of cash at a time as ATMs are plentiful in European cities, but of course your bank may change you fees. I have a bank in the US that will reimburse me other bank's fees so not a problem for me. If that weren't the case and I was paying massive fees, I'd probably take out larger sums of money each time. Up to you.
That's how I get cash. But honestly, I try to pay with a credit card for every transaction I possibly can. Three reasons. First, the exchange rate is usually pretty good. Second, as a security/safety measure, I'd rather not be removing cash from my wallet, stumbling with bills to figure out what's a $5 and what's a $100, and letting other people see how much money I have in cash. Put down the Visa or MasterCard and no one sees my cash. Third, rewards points! But of course, that matters on what kind of card you have. One important note: many credit cards charge a bullcrap "foreign transaction fee" of 1% - 3% of the transaction. It's a nothing fee, made up to take your money. If I had to pay that, I'd be more hesitant about using a credit card all the time. You still have over a month before leaving, so call the credit card company and see what your fee is. If it's not 0%, think about getting a new card for this trip that has no foreign transaction fees. For you Canadians, google for example the Amazon.ca Visa from Chase.
Absolutely, positively the most important piece of advice: CALL YOUR BANK AND CREDIT CARD COMPANIES BEFORE YOU LEAVE. Let them know where you're going and when. If not, they'll cut off your card thinking it's stolen. That's not a good situation to be in.
Also, this may be obvious, but just in case: Danish money is not interchangeable with Swedish money. If you plan to visit Copenhagen in anything more than a cursory way, you'll need both.
Lastly, for the guys, keep you wallet in your front pocket (or a zippered coat pocket), not your back pocket. Best way to avoid pickpockets. For women, get a purse with a larger strap you can put over your head and across your body, not something you have to hold in your hand the whole time. Best way to avoid getting it snatched.