We got travel cards last time we were in Holland. We used them on trains, trams and buses. You just top them up and scan them when you get on and off the public transport. But, when we were heading back to the airport we didn't have the minimum 25 euros of credit on them even though the fare is only 5 or something and the guard tried to charge us 55 euros for the privilege! We politely declined and ended up being escorted by transport police from the train at schipol with our 2 year old on a gruffalo trunks thinking it was the best thing ever as daddy was goin to jail!
In Amsterdam I've done the stadium tour, heinekin tour and a canal boat tour. All very good. Also stayed in The Hague and done madjuredam and went through to Rotterdam for a day mainly for the zoo!