Hi
To get the production order to display the sales order as the source (And only have that sale's production included as with the planning sheet there may be other replenishment included) you need to:
Create a new production order
Select sales order and the sales order number on the top of the production order
Run Refresh from the actions menu
This will populate the production order with the contents of the sale
Depending on the processes in the company and the type of production you may want to have a button developed on the sales order that does this automatically when the user clicks it
Cheers
Nev