Write Format Plugin

Hello Experts,
I would like to know if there exist any good tutorial that can help me in learning Plugin devlopment. I would like to develop “Custom Format Plugin”. I saw sample sdk containing such code. I changed the ouput file genrated to .8bf extension. But when I copy the file to location “Program Files\Adobe\Adobe Photoshop CS3\Plug-Ins (for Windows) or
Applications\Adobe Photoshop CS3\Plug-Ins (for Mac OS).
” and then open adobe photoshop , there was not any change I saw in photoshop. Please I never devlop plugin. So if anybody have any good tutorial for the same , then please help me in this regard.

Thanks;
Vikas