Don't be fooled by the great price at which a place sells foreign currency. The price at which they buy currency will be much lower. "Chequepoint" is rather expensive service. For changing money the train station is the best place. The "GWK" Bank at Central Station has the lowest commissions and they're open 24 hours a day.
Another good place to change might be an exchange office at Damrak 31, they usually have the best rates in the area.
Lorentz company, Damrak 31, tel.: 020-6240945. Open 24 hours.
ATMs are widely available throughout the city, dispensing notes up to 50 Euro.
In Amsterdam (and in the rest of Netherlands) we use the Euro currency. There are 8 coins; 1, 2 and 5 cent, 10, 20 and 50 cent, 1 and 2 Euro coins. Then there are the bills of 5, 10, 20 and 50 Euro, 100, 200 and 500 Euro notes. Not many places will accept the 500 Euro note however. Most of the small shops including supermarkets do not accept 100 and 200 bill as well. Generally, 50 Euro bills remain the most convenient denominations.
How Euros look like see at the Europe's portal: Euro notes and coins. If you are new to Euro, please learn about its security features, not to be fooled by a fake.
It always cost money to get foreign cash. Since credit cards don't exactly change money, they can be a good way to pay (high interest rates on your unpaid balance notwithstanding). However, credit cards are widely used in Amstrerdam and the rest of the Netherlands.