A tour of the environment
Take a look at the tour slideshow:
Then go to GT in 7' videos.
Glamorous Toolkit features a few tools that can be used as entry points.
Lepiter unifies knoweldge management with live programming. Start there with a note and evolve it into a program: A single starting point for scripting, linking and documenting
The inspector offers moldable views over any object (Handling objects through custom views).
For static code we have Coder (Managing code with Coder).
However, these tools can be combined in many ways. For example, a Lepiter page can embed inspectors. And the inspector can show a Coder for editing the class of the current object. All these embedded in a Pager interface that allows us to concatenate larger exploration sessions and form unforeseen narratives.
Oh, and we should not forget about shortcuts, so do take a look at Basic shortcuts to learn about them.