We have been to the Netherlands several times, in fact we've just returned from a week based in Amsterdam.
I highly recommend "Cycling in Amsterdam and The Netherlands" (a spiral bound book of maps, routes and touring tips) by Eric van der Horst and available to purchase on his blog:
The Cycling Dutchman: Amsterdam & Netherlands. We have lent this to several friends, who all report finding it very helpful.
You are in for a treat, cycling in the Netherlands - enjoy your trip!