To start inventory - step by step (Creditor/PO/Bill payment/inventory tracking record)

Hi,

Please guide me step by step from item purchase / payment / creditor / inventory tracking record.

Without to create the quotation to ask quote from Supplier, I already create the "Products & Services" from Supplier Cash Sales (reason I want to create Inventory Tracking list even Cash Bill).

Now, what I already create as per following:

1) Create "Products & Services" and turn on "Inventory Tracking".

2) Create PO#, I can select from "Products & Services" and create the Purchase Order to Supplier.

3) Received Supplier Invoice and make payment.

4) Can I use the PO# I create and post to payment?

5) Can I pull out the PO# to Cash Sales?  I want to key in Supplier Tax Inv ref while payment make.

6) Below step are what i'm understanding, please guide me.

- Create Supplier PO#

- goods received prepare payment

- transfer PO# to Supplier Inv

- Payment to Supplier with Inv ref. - how to update purchase Qty in inventory 

- Just want to make sure after payment Qty will direct update to inventory system or Manually key in?

Hope to hear from you soon.

Thank you.

Chin