Check out UI demo 5 (2D Toolkit 2.2), there are examples of using it in 2 different ways.
To do it in the interface, you put your content under the "Content" gameobject (start with position 0,0,0), and set the content length using the sliders or programatically. There really isn't much more to it, you don't need to deal with the script unless you need to do advanced stuff - the demo above covers advanced use.