Church books at FamilySearch
FamilySearch, the genealogy website of the Mormons, had scans of the civil register for a while now. Recently they also started adding scans of pre-1811 church books: Baptisms, marriages, burials, membership lists and more. Currently available are the provinces Groningen, Drenthe, Noord-Holland, Zuid-Holland, Utrecht, Noord-Brabant, and Zeeland (seven out of twelve provinces).
The scans are made from microfilms that the church had in their collection. They are not indexed and have to be browsed image by image, similar to browsing the films themselves.
To find them on the FamilySearch website, click Continental Europe and browse to Netherlands. While you are there, have a look at the many other resources on their website - there's bound to be a few that are useful for your research.