Citizens of the European Union (EU) and certain other European countries are allowed to live and work in Denmark without a visa or work permit. They must, however, apply for a residence permit at their local police station within three months of entry and provide proof of employment or income.

Citizens of non-EU countries must obtain both a residence visa/permit and a work permit before arriving in Denmark. Residence laws are very strict. Obtaining a residence permit is a very long and frustrating process (even for EU nationals). Residence permits for dependent spouses are even more difficult. It is highly advisable to arrange for accommodations prior to arrival, particularly in Copenhagen. Initial accommodations may be usually found through housing associations (boligselskaber), although there may be waiting lists for the most desirable quarters.

This is just a sample of what you'll find in the complete Denmark guide.