As I was typing the debug instructions, I remembered the original place where I found the tips to debugging in Firefox. This has all the required information.
Here is the link. I cannot think of anything more I know of.
http://www.getfirebug.com/docs.html
At the bottom of the page you will find a link to Install (“Ready to install?”)
This has FAQ, Command Line API, Console API etc. More importantly, there a couple of really good video presentations that take you a long way.
Let me know if you have any specific questions.