If you want to see traditional Dutch windmills there is a small group of them just north of Amsterdam and these are a better choice to make over the windmills at Kinderdijk if you only have time to visit one windmill heritage site.
These windmills were built from 1633 onwards and until 1929 when electric pumps came in to operation these had drained the Schermerpolder to keep it free from flooding as the land is below sealevel.
There is a small visitor centre and it is possible to see inside a restored windmill which does work and is furnshed as a family dwelling would have been over 100 years ago.
The entrance fee is €4 and this represents good value as you are free to climb right to the top of the windmill and see it working (this cannot be done at Kinderdijk).
Train to Alkmaar from Amsterdam CS and then bus 127 to the windmills. By car off the N243.
For GPS / Sat Nav the postcode is 1636 VL.
there are not many working windmills left in Holland. Many of them have been converted to homes. This is a picture of one of the working one's.