There are two ways to load goods into your ship. If you are in the Settlement screen click on the goods at the bottom of the screen and drag them to the cargo hold of your ship. This will automatically transfer up to 100 units (for a standard game). If you want to choose how much to load hold down the Shift key before dragging the goods. You can also load your ship from the overland screen. When the ship is active a load goods icon appears among the other action icons at the bottom of the screen, or you can use 'L'. However with this option you cannot choose a partial load. Welcome to the game janieh.