It’s not only fun, but a convenient and inexpensive way to get around. If you’re going to just ride for one day, get a day pass from the tram conductor or at a vending machine in any train station. You can also purchase “strippenkaarts”with spaces to be stamped by the conductor as you ride. Most rides within the city are in one zone, and take two spaces on your strippenkaart. Each additional zone requires one more space to be stamped. Many trams rely on the honor system, with little clock punchers that you stamp your card yourself with. There is a 60 guilder fine for riding the trams and or subways and trains without a valid stamped strippenkaart.
In spite of all that, you’ll find the tram rides fun, better than walking long distances, and really convenient. It seems there’s always a tram going somewhere, and each stop has very clearly detailed maps of the entire city, and the system. Even if you are not riding the tram, but get lost exploring the city, the tram stop maps can help you find your way to wherever you may be going.
If you are really tram crazy, there is a Tram Museum, and they roll out the old antique trams regularly for tours of the city.