Is there a guide or manual on writing MODs?

[Snowhog]

I'm assuming there must be, or that some of you here who have been writing MODs for a long time have put together your own guides.

I'd like to at least understand the basics; to be able to understand what I'm looking at when viewing an installation .xml file and such.

So, basically, I'd like something akin to an Introduction to vBulletin MODs or vBulletin MODs 101.

[MarkFL]

I published the following:

[vB4] A Beginner's Guide To Creating vBulletin Products (https://vborg.vbsupport.ru/showthread.php?t=318840)

[Snowhog]

Thank you.