Sales Orders reports will help you track products that need to be shipped or invoiced.
To access these reports, go to menu 'Intelligence':
And click on the report you are interested in:
Reserved items: List of your products included in Sales Orders but not yet in Shipping Orders. They are also included in the Reserved Inventory column in your Stock level.
Uninvoiced items: List of your products included in Sales Orders but not yet in Invoices.