I am headed back to Netherlands soon after a few years and was reading some threads and saw this
I took my sister and 1 year old niece to Amsterdam a few years back and had some GREAT memories.
http://www.futuregringo.com/index.php/2008/03/25/you-have-a-baby-in-amsterdam/
I would try and get an apartment or someplace with a small kitchen. Makes it easier to prep food, eat small meals in and saves money instead of just a standard hotel room.
Other tip - Bike City in the Joordan has a couple bikes with kids' seats. Although young my niece LOVED cruising down the streets in the front seat and through the park.
enjoy...