Friends on bike
Friends on bike is a volunteers organization that provides Bed an Brakfast service for people travelling using musle power, bike, hiking, skating, etc. You have t be a member of the organization. They will send you a list with 3700 address in Holland and Belgium where you are welcome to stay for a modest amount of money. It's a good chance to meet the Dutch or Belgians.
Check the web site of Vrienden op de fiets for more information. There is a page in English for your convenience, explaining the whole concept, including prices.