Money

All airports, and most larger train stations have currency exchange desks. Wherever tourists congregate, there will always be exchange bureaus around: http://youtu.be/Ur7NgbJ1G30

Obviously exchange money needs to be done at a bureau but be aware the rate at an exchange bureau will be poor to very bad. Obtaining local currency via an ATM is the cheapest and most convenient way.

When you say "exchange money," are you asking about literally changing cash from one to another? Or just the best way to obtain local currency? The best way to get local currency is always by using your ATM card. Your bank may charge you some fees, usually no more than 5% over the actual interbank exchange rate. Always notify your bank of your travels and have a backup card (ideally from a different account). Some credit unions and online accounts charge few or no fees and many find it worthwhile to set up an account. A search will reveal many options. As described above, actual exchange agencies will change your money for you, but you pay 10% or more over the interbank rate. You can also buy some local currency in the US, large banks and organizations like AAA provide that service for a fee. That costs between 5-10% over the actual rate.

When I was in Prague on May 23, I saw an exchange shop advertising "No fees". They were giving you 18 Czech Koruna for 1 USD. According to Oanda, the Interbank rate at the time was 19,73 Kc per USD, so you would lose 8.77% if you exchanged dollars for koruna. I used my ATM card at an ATM at the train station and only paid an extra 1% (plus a $2.50 charge for using an out-of-system ATM (total about 2%).

ATM cards are the best. . . exchange rates are usually the best you'll get and the machines are everywhere and always open. The best thing is to open a Capital One account online and get an ATM card because they don't charge fees for withdrawals. Many US banks will charge you either a percentage or a flat fee ( about $5) or a combination. If it's a flat fee, you tend to take the maximum each time, to keep the fees lower and then you have to carry all that cash around with you. Another tip - you can use "leftover" cash to pay part of your hotel bill when you leave. Although German hotels and many restaurants take credit cards, most stores and smaller restaurants don't. You will need more cash there than other European countries. A friend of mine living there said he was surprised when he went to Ikea in Berlin and they didn't take credit cards either.