Let us suggest something away from the obvious (Amsterdam, The Hague, Delft, Gouda).
(small note: we will underline terms and names that you can easily look up on Google and Google Maps to orientate yourselves).
If you like small historic villages, and you arrive in Amsterdam, then we would suggest a round along the old coast of the
Zuiderzee (now
IJsselmeer, since it was closed off early 20th century with the
Afsluitdijk). You will be visiting lots of small 16th/17th-century harbour towns that are now mostly very quiet, but were once lively and rich towns, all supporting the big Amsterdam sea trade industry of the 17th century. Make it a point to take the old dyke roads where you can. We have done that tour ourselves, and it is beautiful and mostly surprisingly quiet.
From Amsterdam, roughly do:
Durgerdam,
Uitdam,
Marken,
Monnickendam,
Edam (forget Volendam - it's a tourist trap, Marken is, too, but more charming),
Warder,
Hoorn. (Close to that route you may want to visit the
Beemster polder, it is an old polder, UN Heritage).
Then
Enkhuizen (you may want to visit the
Zuiderzee museum there, or take a ride on the old
steam tram to Medemblik),
Medemblik,
Wieringen,
Den Oever,
Afsluitdijk. Depending on your time, you may want to do a round of
Harlingen,
Franeker (visit
Eise Eisinga's Planetarium there!),
Bolsward,
Makkum. Or go directly to
Makkum, and from there
Workum,
Hindelopen,
Stavoren. Follow the coast to
Oude Mirdum and then
Lemmer.
From there to
Kuinre and
Blokzijl. Leave the old coast shortly for
Giethoorn, and then through the
Beulaker/Belter Wiede to
Vollenhove,
Zwartsluis,
Genemuiden,
Kampen and
Elburg.
Once you are in Elburg, from there you may want to visit the
Kröller-Müller museum. Then
Amersfoort,
Naarden,
Muiden (visit the
Muiderslot) and back to Amsterdam. We think you can plot most of this on Google Maps.
If you want to visit larger towns such as Amsterdam, Delft or The Hague, indeed do bring your bicycles. Park on the outskirts, and cycle wherever you want to go!
You should know that wild camping, or sleeping in your car when parked, is NOT allowed anyhere in The Netherlands! Only on designated areas such as camper sites or campings.
There are many camper sites around the country, but we never stay there. They are most times a sort of car parks, with lots of those big white giants in rows and rows next to each other. We wouldn't want to be found dead in such a place, but each to his own.
If you like to stay on smaller camp sites, you may want to look at 'Camping at the Farm'. Many farmers have small camping facilities. You can join their organisation
SVR Foundation for € 10 a year, and then you can use their website and guide to find participating farmers and use their facilities. When in NL, we do that all the time.
If you decide to visit Utrecht, give us a shout! We could meet up for a drink and a beautiful medieval town visit.