Ok, I'm not sure what you mean with my people.
But in order to add any object to the map, you need to open the "objects tab" inside the map maker.
It will give you a few standard groups to choose these objects from.
Press any of the object groups, then in the window below, mark the object inside the group you want to add, then click the button "Add new". This will replace your cursor with an object, and you need to click somewhere on the ground in order for it to be placed.
Once you save the map, the object that you placed will be saved there aswell.