Do you want to write an extension or some Custom Buttons code ?
First page to visit should be:
Mozilla Developer Center contents
Drop enabled button for silent installation of drupal modules.
Example how to have a button with drop and click.
A web form where you can add urls to go generate
a custom button.
A button with menu for all relevant Quick Macros links.
Button for showing the bbcode menu.
The BBCodeXtra extension is required.
How to fix the 'sec_error_untrusted_issuer' error.
hide custom button links for non firefox users
I use a javascript function to display content when you
visit my site with firefox.
i need to explain that.