Dynamics GP has the ability to quickly process drop ship orders. Typically in a drop ship situation, your customer will place an order with you. You will then create a purchase order to your supplier and instruct them to ship the product directly to your customer. Once your supplier has shipped the product, you will enter the vendor’s invoice to accounts payable and invoice your customer. You can use this process on a single order basis or process orders in bulk.
This post gives you more detail and images on drop shipments.
Or you can go right to this video.