Any caveats for driving in NL?

We picked up a rental from Hertz on Overtom Road in Amsterdam. It was just a few blocks from there to the highway and very easy to get to on the tram.

No special tricks for driving in the Netherlands, other than following the same rules of the road in the rest of Europe. No equivalent of ZTLs of which I am aware. Like the rest of Europe, radar cameras are the primary method of enforcing the speed limit, so make sure you understand the implied difference between urban and rural speed limits. Cities are less car-friendly than the European average.

As long as you plan daytrips to cities public transport will be more convenient for you to travel around in the Netherlands as most places are (most) easy to reach with train and bus. If you have the plan to visit the countryside and remote villages like in the north-eastern and south-western corner of the country you can think about using a car. For visiting the mills of Kinderdijk you can take the waterbus from Rotterdam or Dordrecht, the latter worth a visit too. So plan first and see if a car is really what you need.

If nevertheless using a car be aware of various speedlimits and strict law enforcement.

Totally enjoyed driving in Nederlands, going to the beach, out to Delft and Haarlem, etc. A GPS is a great help, and your phone ( I have TMobile) may have a free or a well priced data plan. We used to use a TomTom but started using Google maps. Have picked up and dropped off cars on Overtoom, have turned one in near Centraal Station. Yo don't need to go out of town to get a car and leave as some people suggest with Paris for example. Take the insurance tho, or get it as a rider on your travel insurance- and know that the insurance is about the same price as the rental. Of course you will not want it until you are leaving Amsterdam.