How can multiple network players control one gameobject?

I am trying to figure out how to have two (or more) players connect and cooperatively control one gameobject. My idea is to build a couple of different vehicles, like tanks where one player drives and the other player shoots. I have followed a couple of tutorials and spent hours of searching. I can connect the two players but I am lost on how to get started. Could anybody describe the types of gameobjects and network behavior I will need to creat?