Groningen is a sweet town - definitely worth a 25 euro train ride from Amsterdam. Lots of Pubs, big student population, this town rocks until 6 in the morning.
The best thing about Amsterdam (that isn't inhaled) are all the cheap falafel places. Look for one with a bar that lets you add your own toppings.
This small city is really really beautiful! Enjoy walking through the old streets and take a sit in the Grote Market, the central square of Haarlem -- full of life during the day and with some pubs and street musicians at night. It's peaceful, but not boring!
The winter Carnival in Bergen Op Zoom is superb, a true folk festival of the highest order, lasting several days, highly recommended. On a Fastavond you can squint your eyes and imagine you are back in the 1700s, as the bands march about, and the colorfully dressed villagers sing and celebrate. This area is very family …
I lived in Soest as a child. It was so wonderful, quaint, and friendly. I can't wait to take my children to see how non-Americans live.