First and foremost:
http://www.undutchables.nl/

Dutch government: immigration services:
http://english.ind.nl/

Big job boards:
http://www.stepstone.nl/
http://www.monsterboard.nl/
http://www.expatica.com/
http://www.xpatjobs.com/ (not familiar with this one myself)

Recruiters:
http://www.iamexpat.nl/career/looking-for-a-job/recruitment

General help:
http://www.expatica.com/nl/essentials_moving_to/essentials/Looking-for-work-in-the-Netherlands_13189.html
http://movetonetherlands.com/study_work.html

More links:
http://www.access-nl.org/living-in-the-netherlands/working/finding-a-job.aspx

Something to help with the transition:
http://stuffdutchpeoplelike.com/