In Denmark the standard voltage is 230 V. The standard frequency is 50 Hz. The power sockets that are used are of type F / K. Read more: http://www.power-plugs-sockets.com/denmark/
In Denmark the currency is called kroner (abbriviated 'kr'. or 'DKK'). Shops normally don't accept Euro. You will find ATMs on every street corner in the cities. All banks has at least one ATM outside every branch. You will also find an ATM just after the customs office at the airport. Most shops accept international credit cards.
According to Danish law, any service charge, including tips for waiters, has to be included in the price in restaurants. It is not common practice to tip the waiter unless you have had an extraordinary experience at the restaurant.
Read more about the topic here: http://www.tripadvisor.com/Travel-g189512-s606/Denmark:Tipping.And.Etiquette.html