How Do We Take Stock?

Taking stock is a term referring to a yearly (sometimes more frequently done) check of what you have in inventory. This will allow you to determine what items need to be re-ordered, avoided in the future due to poor sales, or written off entirely due to damage. (All of this information is very useful in managing a business efficiently, shareholder info, tax purposes, etc.). Every business/industry has it's own best way of going about this. So you'd have to be more specific about which market you're referring to.
But what I mentioned above is the basic taking stock model.
Hope that helps.
I wish you good luck and God-speed.