Use the Transport Ledger to determine which resources will be transported from the countryside to the industry of your nation. 

At the start of the game, the only resources you can transport are all from the area surrounding your capital. After your Engineer builds railroads, depots and ports you will be able to transport resources from deeper into the countryside.

The amount and types of resources available will increase due to the work of civilians such as Farmers and Miners.

This turn you should make sure you are transporting everything you have available. If not, increase the amounts of commodities being transported.