Want to learn more advanced stuff about how to use Ext JS?
Check out these slides from an Ext JS core developer named Aaron Conran. You might know him from the Ext JS forum.
The next presentation teaches you about Ext JS Event Handling:
Next a presentation about Ext JS Observable Class which includes a nice example of how to catch all fired events of an object and print them to your firebug console.
Ext JS's Dom helpers should also be checked out!
Thanks Aaron for putting together these very helpful slides!