Bureaucratic procedures exist in every country for expats relocating and the Rhine Ruhr region of Germany reveals no exception. The rules are generally clear, if somewhat complicated.
In general, anyone who plans to remain here for more than three months will need to register with the local authorities, ideally within the first week after arrival. The procedure then depends much on country of birth and nationality.
One great achievement of the EU and its institutions is that most of its 500 million inhabitants can relocate across borders relatively easily. The Residence Act (Aufenthaltsrecht) is a complex paper, which reveals most answers for all the global nationalities. Freedom of movement in the EU exists but has strict rules, such as the neccessity of posessing health insurance.
In the districts of Rhine Ruhr normally a brief trip to the Einwohnermeldeamt or the local Bürgerbüro with a completed registration form and a valid passport or official ID along with employment details is all that is required.