Bike tours near Delft, Leiden, The Hague

bike rental companies Leiden:
http://www.fietsverhuur-leiden.nl/en.html
https://www.easyfiets.nl/en/
https://www.huurmij.nl/fietsverhuur/

bike rental companies in Delft:
https://www.wijtman.nl/fietsen-huren-in-delft-en-vlaardingen
https://fietsplusdelft.nl/rental-bikes/

You can plan your own route via https://en.routeplanner.fietsersbond.nl
explanaton about the numbered junction system: https://bicycledutch.wordpress.com/2010/03/01/netherlands-numbered-junction-bicycle-network/

or choose one of these around Leiden:
https://www.nederlandfietsland.nl/knooppuntroutes/molen-fietsroute-leiden-en-kagerplassen
https://www.route.nl/fietsroute/115733/leiden-en-het-kaaggebied
https://www.nederlandfietsland.nl/knooppuntroutes/fietsroute-langs-de-limes-van-katwijk-tot-leiden
https://www.visitleiden.nl/uploads/fietsroute_stad_kust.pdf

or one of these around delft:
https://www.nederlandfietsland.nl/knooppuntroutes/delfland-fietsroute
https://www.toproutenetwerk.nl/media/Tops/Delft/Acker-%20en%20Bieslandroute%20vanaf%20TOP%20Delft.33km.jpg
https://www.toproutenetwerk.nl/media/Tops/Delft/Delflandroute.31km.schermversie.jpg
https://www.fietsnetwerk.nl/fietsroutes/fietsroute-rond-delft/

self-guided tour of one of these cities
A bicycle is only useful for exploring the countryside outside Delft or Leiden. If you plan to visit just a city itself, walking is by far to be preferred. The historical centres of both Leiden and Delft are compact (you can cross both in less than 30 minutes), and the railway stations are in both cities less than 10 minutes walk from the centre.

Thank you so much for the links and suggestions!

We just got back from nine days in the Netherlands and rented bikes two different days. We should have planned better and gained a better understanding of where to ride. We rented bikes in Delft and Haarlem. I would not try to ride bikes in Amsterdam. In hind sight, we should have signed up for a bike tour.