You can't buy on-line from the Dutch railway website...at least, not yet. For the Hague to Brussels and Brussels to Rotterdam, use the Belgian rail network site (http://www.b-rail.be/main/E) and click on "travelling in Europe" down the left side....you must register, but it's easy to do, and you can pay by credit card. You'll print off your ticket at your home computer. You can book those journeys up to 30 days in advance. Travel by the InterCity (IC) express trains....cheaper than Thalys and only a few minutes longer travel time. As for your other journeys, it's virtually impossible to use a credit card for local rail travel in the Netherlands...but fares are cheap....Rotterdam-Amsterdam is under 13 Euro, second class. Just get to an ATM before you buy (there are usually ATMs at the larger stations) and use the machine (with coins) or the ticket window to purchase. The country's rail system is more like a gigantic commuter rail service.