If you're planning on moving here, be prepared to wait to enroll your kid. It'll probably start with a half-day here and there with places opening up over the months. The cost, at least in Alkmaar, is around €6 an hour and they bill right away. If someone is working, you can qualify for government help. The website is http://www.toeslagen.nl/
There are different programs that you'll need to download and fill out, depending on the the type of assistance you are looking for.
1) Huurtoeslag (for the rent)
2) Zorgtoeslag (for medical insurance)
3) Kindgebonden budget (for new borns)
4) Kinderopvangtoeslag (for the daycare)
Keep in mind each year, you'll have to download a new program and yes everything is in Dutch, so you'll need Google translator if your signifigant other isn't a native speaker.