More links for developing firefox extensions

http://digg.com/programming/How_to_create_a_Firefox_extension_step_by_step_tutorial

http://www.businesslogs.com/technology/firefox_extension_tutorial.php

http://www.borngeek.com/firefox/toolbar-tutorial/

http://digg.com/programming/How_To_Your_First_Firefox_Extension_Say_XUL