If you are not Dutch and non-EU you most likely need a visa and/or resident permit.
You will find the necessary information about how to apply for a visa on “The Visawizard” (see link below). Select your country and The Visawizard provides you with a detailed step by step plan on how to get a visa. It is very important that you apply for a visa as soon as possible, since it might take more time than you would expect. The costs of a visa for the year 2013/2014 will be around €320.
The University of Amsterdam (UvA) provides immigration services to international AUC students for student residency; for more information please follow the link below to the “Visas and permits” webpage of the UvA.
Link (eng): http://www.uva.nl/en/education/master-s/practical-matters/visas-and-permits/visas-and-permits.html
Since you will be living and studying in the Netherlands longer than three months, you will need a resident permit. A resident permit is generally issued for one year, so keep in mind that you will probably need to extend your permit every year. The general costs for extension will be €150. In this case the UvA will provide all the necessary information and assistance to help you get your residence permit. Please find the link below.
Link (eng): Visa's and Permits
For more general information on coming to the Netherlands to study, you may like to visit the Study in Holland website, an initiative of the Nuffic (the Netherlands organisation for international cooperation in higher education), and/or the immigration website of the Dutch government and Dutch Immigration and Naturalisation Service (IND).
Link (Nuffic): Nuffic