Devlounge | How to Write a Wordpress Plugin
www.devlounge.net/extras/how-to-write-a-wordpress-plugin
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
How to Write a Wordpress Plugin, written by Ronald Huereca is an extensive, twelve entry series on the process of creating your own Wordpress plugin.