Addon Development Basics


I am new developer in cs cart with limited knowledge.

I have read developer and designer guide as well but my question is about developing an addon.

first of all I want to know some basic steps to develop and addon (not hello world or advance addon tutorial), I want to learn steps by one example addon.

for example I want to hide and display sku number on grid view of category view than what steps I have to follow and also the admin should be able to enable and disable sku if it should be visible to users or not.

Please explain to me steps.

and one more question that where from we get these arrays data?




I mean if there any specific location of these variables please let me know where it is?