Help needed on inventory database architecture in Access 2003

Hi all,
I need to develop Access inventory database for a small family business shared on the network between two computers.
What it needs to do is:
Manage customers and their credit accounts (broken down in periods of 0-30 days, 30-60 days, 90 and over)
Account customers can be assigned to a discount percentage so when generating invoice price is automatically deducted for each product.
Manage suppliers
Create PO's for suppliers.
Manage products
Receive products
Manage sales
Invoice customer (there will be counter sales "cash" customers as well as credit account customers)
Multiple users? (since database will be shared over network although there will be no security issues as it is isolated from the Internet)

Cost price for products is constantly changing, which means today I buy a certain product for one price, next time more than likely will be new price for the same product.

What I am looking for is database architecture, list of tables, possible fields, list of forms and queries. Also general experts advice on what to watch out for and best practise in development.
Also I would be looking for an advice on what reports are "must" have reports (sales history, product movement, customer account balance...?)

At the same time I'm trying to keep it as simple as possible without any unnecessary stuff. Samples I've found on the Internet were either too simple or overcomplicated systems. And can't spend anymore time looking for something that is possibly not there. I'm relying on you experts.
It didn't allow me to give you more than 500pts for this question :((

Thanks!