Breaks down like this. The OV chipcard is available in major train stations - when you buy it, you charge it with a certain amount. This chip card works in any means of public transport everywhere in the country. When you board a tram, bus, train, or subway, you ‘check in’ - either on the vehicle (bus, tram) or on the platform (train). Then, when you get off, make sure to check out - the chip will then calculate the cost of your ride and deduct that from the credit on your card. You will need a minimum amount to be able to check in - 4 euros for bus, 20 for train. If you forget to check out, you’ll be charged that full minimum amount, which is very upsetting. I took the train from Schiphol to Voorschoten, a 20 minute ride that would normally be 3 euros or so, and it cost me 20 because i forgot to check out. For train travel, you can avoid this risk by buying a ticket, either from a window (big stations still have them, but you pay 50 cents extra) or from a machine. IME, the machines won’t take N American credit cards since those tend to not have a chip. They also don’t take euro notes, as was mentioned up thread, so that makes them less than useful if you don’t have a European bank account.
As for what ticket you need, it’s hard to believe that a country-wide day-pass for 52 euros would pay off for most of your trips. I’d just go to the window, announce your destination and ask for a return ticket. Then figure out how much city public transport you might want to use. Now in city transport (buses, trams, subway) tends by now to require the use of an OV chipcard. I’m sure each of the individual city transporters (RET in Rotterdam, HTM in The Hague, etc.) might sell day passes that may or may not pay off, it depends on whether you plan a lot of walking (or maybe biking). These, however, would only be usable in one city and one city only, you can’t buy a daypass in Rotterdam, and use it in The Hague. Many smaller cities don’t have their own public transport and would not have a daypass. There you’d either have to buy a ticket on the bus, I guess, which I think is still possible, or use the OV chip card. If you got an OV chip card, you’d be able to use the credit on it in any city and that would be a plus.
Hope this helps. It’s not as confusing as it might sound, and to the extent that it is confusing it’s because right-wing fucktards decided it was necessary to replace the perfectly functioning and readily understandable system that was in place with this OV Chip card clusterfuck. Sorry about that!