Victor Gaudioso has written a nice tutorial on “Setting up a Development Environment and Using gProject to Create Custom Classes” on ActionScript.org. It covers the basics of setting up a project, creating classes, and auto generating properties for on-stage interface elements.
You can check it out here.
Hey Grant, I am glad you liked it. John Grden taught me and I have been addicted to gProject ever since. So I figured I would help out the next Flash developer and made this tutorial.