Free genealogy sources

Digital Family Tree Rotterdam

If you have ancestors from the city of Rotterdam, you might want to check out the Digital family tree, created by the city's archives. They have transcribed and uploaded the majority of the death, burial, birth, baptism, marriage and divorce registers from Rotterdam, as well as of some of the surrounding locations, notably:
Rotterdam
Bergschenhoek
Berkel en Rodenrijs
Bleiswijk
Charlois
Cool
Delfshaven
's Gravenambacht
Hillegersberg
Hoek van Holland
Hoogvliet
IJsselmonde
Katendrecht
Kralingen
Overschie
Pernis
Schiebroek
This is an invaluable genealogical source, since it allows users to trace their Dutch ancestors back for hundreds of years; the earliest records start in 1573 and end in 1950. The search engine allows specifications and wildcards, thereby greatly facilitating genealogical queries.

you can find the Digital Family tree of Rotterdam here:

http://www.gemeentearchief.rotterdam.nl/content/index.php?option=com_content&task=view&id=14&Itemid=56&lang=EN

Civil Register of the Netherlands

If you have Dutch ancestors, you can easily trace back your ancestors till 1750-1780 through the Civil Registers, that contain birth, death and marriage records. The civil register in the Netherlands was created under the rule of Napoleon Bonaparte in 1811, and since then every marriage, death or birth had to be registred.
A large portion has been digitalized at this internet address. You can trace almost any Dutch ancestor that lived in the 19th century. Large segments of the Civil Registry have already been digitalized, and new entries are continuously added to this incredibly genealogy source. At the moment, the website of the Civil registry project contains already a couple of million entries. You can browse their website for free, and reconstruct the households and family trees of your ancestors without leaving the house. You can find this genealogical database here: Genlias
This should be the starting point for all genealogical research in the Netherlands.

Amsterdam Census 1852-1853

An excellent database containing more than 600.000 entries on inhabitants of Amsterdam between 1852-1853 was compiled by the late genealogist Dave Verdooner and eager helpers. In memory of his genealogical research achievements (especially with regards to Dutch Jewry), the organization Akevoth for the study of Dutch Jewry decided to host this invaluable database. For anyone with ancestors in 19th century Amsterdam, this database provides plenty of search options :name, address, religion, often also birthdate, date of admission to the city. With a bit of exercice, you will be able to easily reconstruct entire households.
You can find the database here: http://dave-verdooner.net/