Intro to creating plugins/addons?

[sweeps78]

I've been a vBulletin admin for several years now. All the mods that I have on my forums have been created by all the awesome folk at .org, thanks!! I'm a programmer by trade (mostly .NET) and up till a year ago, wrote little php. However now, I'm finding myself to be more and more proficient at PHP, so I want to test my skills and create my own plugin. But, I can't seem to find any type of introduction to creating my own plugin. Is there an intro that everyone uses? I just want to create some very basic for now, but I'd like to know all of the basics of creating plugins before I royally screw up my forums. I've gone through the vBulletin API manual and also looked through many of the articles here, but haven't found anything yet, so I thought I'd ask here. I'm sure there's something very basic I'm missing.

EDIT I also looked at the vBulletin manual (http://www.vbulletin.com/docs/html/creating_a_product), but I was wondering if there was anything else

thanks!