If you are a national of a country that is part of the European Union (EU), the European Economic Area or Switzerland, you are legally entitled to stay, work and look for work in the Netherlands. You do not require a residence permit; a valid passport (or ID card) from the country where you are a national is proof that you legally entitled to stay and work in the Netherlands.
Every non-EU citizen who wants to work in the Netherlands has to obtain a work permit (TWV - tewerkstellingsvergunning). In general, employers who wish to bring into the country a non-EU employee, are responsible for their work permit application. The employer should hand in a copy of the work permit application, on behalf of the employee, to the UWV WERKbedrijf, which is responsible for informing IND (Immigration and Naturalization Service) about the status of the application. Every non-EU employee must have a TWV (where applicable) in order to obtain an MVV and / or a residence permit. If an MVV is not required then you can apply for the work permit after entering the Netherlands.