Expat Focus provides information and resources for expatriates for a large number of countries, including the Netherlands. The website also host forums and blogs for expats.
Just Landed provides expat information on the Netherlands as well as a forum.
Holland.com is the website of the Netherlands Board of Tourism and Conventions.
Lonely Planet Worldguide provides a lot of useful travel information. Check out the link for the Netherlands.
Rough Guides Destinations offers much useful travel advice and information for most countries, including the Netherlands.