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.