For longer stay you would need to find a room on your own or sharing with other students. The best way to find one is via kamernet or post on their facebook page. Register and search is for free.
The Natural Campsites of the Netherlands are a cheap option to enjoy nature reserves at its best. You will have to buy Het Groene Boekje (the green guide) with the natural green pass to access the 136 campsites, that are equipped with clean sanitary facilities, hot running water and electrical power.
If you are seriously looking for a house you have to search the Funda platform, the association of real estate brokers that lists all available houses at the time. Search per zipcode and area and get somebody who speaks Dutch to help you find a place.