North Holland
Haarlem - The peaceful town of Haarlem is just a short train ride from Amsterdam, and it's an easy day trip with kids.
Teyler Museum (Spaarne 16) - You might pass right by the small Teyler Museum, but don't! Built in 1778, this is an old-world, eclectic museum, filled with fossils, dinosaur bones, crystals, and all kinds of 18th and 19th century scientific instruments.
The raising bridge across from the museum is a great place to sit and watch the boats go by. If you're patient, the bridge will raise up to let the boats through. Also, take a stroll along the river Spaarne and the canals.
Frans Hals Museum - It's worth a visit to the Frans Hal Museum to see his wonderful portraits of people, so real, you might expect them to talk. Look for his paintings of good Dutch cheese and the Civil Guard (check out their swords). Don't miss an exquisite dollhouse, filled with minitaure furniture. Admission is free for kids.
Grote Kerk of St. Bavo - Stop into this Gothic style church. Inside, look for three marvelous wooden ships, hanging like chandeliers from the ceiling and carved coats of arms on the walls. The church has a fabulous pipe organ - check the schedule for concerts. In the square in front of the church (Grote Markt) there are weekly markets and look for kids playing soccer.
Kennemer Dunes National Park - The Kennemer Dunes National Park has lots of well marked trails that meander through a natural landscape of ponds with ducks and swans, small forests and open land reminiscent of Maine. Great hiking for kids of all ages, there aren't a lot of steep places. There's a great sand beach and swimming for toddlers at the 'T Wed pond.
When you get to the beach, it'll be crowded with Dutch families, rain or shine. (If you don't feel like hiking through the park, you can drive to beach too.) Further south, Zaandvoort is a big beach resort town, with a big amusement arcade and car racetrack.
Volendam - On a Sunday, head out to Volendam, a charming old fishing village where you'll see people in traditional dress (and if you like, you can put on a costume too, great for adorable pictures.) There's demonstrations of cheese making, a ceramics factory, and blacksmith.
From the Volendam harbor, take the Marken Express boat ride to the quiet little village of Marken. The perfect place to picnic on a nice day.
Visit a cheese museum (Alkmaar) - In the center of Alkmaar is a lovely old building that was once the weighing house. Today it is a small cheese museum. Find out how Dutch cheese was made traditionally and see the old carved wooden cheese presses. The gift shop has lots of trinkets with the cheese theme. On Friday mornings (April- Sept.), you can see a demonstration of the traditional cheese weighing.
Ride a steam train (Hoorn) - From Hoorn, you can take the steam train, "Stoomtram," to the town of Medemblik. Bright red and puffing out clouds of steam, the Stoomtram is filled with Dutch families on a day outing. If you didn't bring a picnic, snacks are served on the train.
Medemblik - Visit the Kasteel Radboud (Castle Radboud). This castle is not particularly big, but it has a moat, armor and coats of arms in the main hall, plenty of charm and possibly ghosts, although we didn't see any.
Don't miss the delightful park next to the castle. The park has a small urban farm with ponies, goats, sheep and chickens, a miniature golf course and restaurant with thatched roof and flower garden.
Zuiderzee Museum (Enkhuizen) - This open air museum shows life in typical Dutch fishing village at the end of the 19th century. You arrive and depart by a short ferry that takes you to the museum site, then you can wander around the "village" as you like. Kids can dress up in wooden shoes and traditional Dutch clothing. We visited the schoolroom and tried our hand writing with pen and ink (it's hard, both the benches and the writing).