Plugin_help

Hi
I am new to LibreCAD. I am trying to contribute to LibreCAD by developing  a new plug-in .
But need your help. Please suggest me from which step should I start?
Is there any tutorial guide related to plug-in?

Read:
http://wiki.librecad.org/index.php/LibreCAD_Plugin_Development

The files  librecad/src/plugins/document_interface.h & librecad/src/plugins/qc_plugininterface.h
are self-documented.
As example you can read files in:
https://github.com/LibreCAD/LibreCAD/tree/master/plugins/sample
https://github.com/LibreCAD/LibreCAD/tree/master/plugins/align
https://github.com/LibreCAD/LibreCAD/tree/master/plugins/sameprop
https://github.com/LibreCAD/LibreCAD/tree/master/plugins/list
https://github.com/LibreCAD/LibreCAD/tree/master/plugins/asciifile

These links are listed in order from simple to complicated

Thanks!!