Biking Haarlem to Keukenhof Gardens

What you hear is correct.

The wind in the Netherlands, and Holland in particular - you will be in both North and South Holland - is what makes all those scenic windmills go round, and nowadays generates so much of the Dutch electricity.

You will certainly know if you are biking into the wind or if it is to your back. Mostly it is an onshore wind so will be a crosswind.

You will be alongside a canal for part of the route, and through a forest for a different part - if you look carefully you can find a tasty pancake restaurant at a rest area in the forest.

I've done it and it is a lot of fun, and you can ride on tiny lanes next to many bulb fields towards the southern end of the ride.

If you get too tired biking you can ride a train back - just be sure to buy a ticket for the bike.

It’s a beautiful easy ride...we thoroughly enjoyed it. Don’t worry about the wind. Biking in the Netherlands is a joy as the country actually encourages biking and drivers are more than courteous, especially those more accustomed to single track and former logging roads.

Dutch winds are very much exaggerated. Most of the time it's just weak or moderate (3 to 4 Beaufort). And the wind against you one way will be with you the other way.
Use OpenStreetMap for the best route (zoom in for more detail). Make it a circular route: one way along the mid-17th-century Leidsevaart; the other way along the canal enclosing the huge Haarlemmermeer Polder. In Cruquius you've got the impressive mid-19th-century pumping station of the same name. A few hundred metres further on you've got a small bridge over the canal. Use it to get back to Haarlem along the Spaarne river.
Have good weather!

Thank for for the great advice and words of encouragement. We are going to bike it!