Need suggestion for firefox addon development

I want to develop a firefox extension for my website. I have some basic knowledge of XML the firefox extensions also require XML but there also some other stuff required. I am unable to find any comprehensive tutorial or book for it.
All I need for my website is an addon which can post some data from users website to my website without requiring the user to load my website.
It will comprise of some text fields and a textarea.

Can any one suggest me any tutorial that can be helpful?


Hopefully it’ll be back up soon, but the official Mozilla XUL reference is pretty good. When it’s online. Ahem.

They also have a tutorial:
(also offline, gak!)