Advice on self-guided cycling tour.

The loop you intent to make, seems logical to me. It'll depend on the side-trips that you plan to make, or that just seem a good idea, once you're on your way, how long it'll take you. Of course it also depends on your cycling capabilities.
Although there are some straight routes for your intended loop, some detours might be interesting.
1. Going from Amsterdam to Utrecht go along the Vecht-river
2. From Utrecht to Gouda it makes sense to go via Linschoten, Oudewater, Haastrecht to Gouda
3. From Gouda to the Hague, you could go via Gouderak, take there the little ferry to Moordrecht and then on to the Hague. The problem here are the Rottemeren. You can only cross these in Hilligersberg, a suburb of Rotterdam or along the motorway or even further north at Moerkapelle.
4. From the Hague to Zandvoort, take the cycle-path through the dunes.
In the ViaMichelin-website you can check the possibilities. Select "cycle" for the possible bike-routes.

Cheers redzed,
As to accommodation and bike rent, this package might be a good solution.

I didn't check if your required itinerary can be done on basis of this cycle-friendly hihostels (former youth hotel, in NL named Stayokay).
But Amsterdam, Rotterdam (nice/special hostel architecture), The Hague and Haarlem are part of the deal.

I would add to the good advice by Liberat the relevant part of the North Sea Cycle Route (just google).

After checking I realize the package is limited to one hostel/more days.
I remember there was a possibility to cycle to other hostels, renting the bike in the first one.

Sorry for this mistake, anyway the link might be useful for you - or other cyclists.

Thanks for the replies. I will be researching side trips from our planned route and will take Liberat's suggestions into account. Also thanks for the link to the Stayokay link. Some of the hostels look promising as they have private rooms for two. We are a mature couple and the shared accommodation days are past.

Great idea! The Netherlands are perfect for cycling, with special bike lanes, signposted scenic routes and flat land. (But sometimes strong winds and/or rain too!)

Have a look at this thread for lots of advice about scenic cycling routes.

And for accommodation have a look at http://www.vriendenopdefiets.nl/ > cheap lodging and breakfast for cyclists. You need to become a member first (membership is also cheap). A great way to have a warm bed for cheap, a hot shower, hearty breakfast... and get a peek inside Dutch people's homes or farms! :-)

Try to include the cute town of Oudewater in your trip. It's near Gouda and is super cute.

Personally I prefer to see how the wind blows that day and then cycle according to that... making sure I have the wind in my back on the last bit. For example a loop starting with head wind and ending with back wind, or a trip from A to B with back wind. But that makes it harder to book the accommodations.

You can also bring a bike on a train for 6 euros per day per bike, you need a special ticket for your bike. In case it rains cats and dogs... :-)

Have fun,
Cécile
Amsterdam

By the way, in my old post I mention an ANWB shop on Museumplein in Amsterdam but it moved to a place further out of the center unfortunately. But in Amsterdam you can buy good cycling maps at shops called "Pied-a-Terre" or at "A La Carte". Tell the shop attendant what you plan on doing and they will help you.

I think in your case a map that includes 'Knooppunten' (reference points / numbered connection points) is a good idea as well.

If you have an iPhone look into apps like "Fiets!" (which enable you to plan your own route along those numbered 'knooppunten') and ANWB apps with the word 'fiets' in them.

Good info. Thanks Cecilia.