"do i just click on that to put the materials on the base?"
..you mean your asking without even trying first?
The facility you're trying to unload to must have the load limits set to the amount, or higher, of each material you are trying to unload. This can be done in the Building Management section of show stats via the inventory or by going to the buildings control room.
Then all you have to do is dock or be above the top left corner of the facility (might work elsewhere above the facility I just always go there) and click unload, then click where you want to unload it, then enter the amount you want to unload and click the button.