Starter Motor Connections

[brainbug007]

Yup I've got that the big black one I had on the starter needs to go to the gearbox. The alternator was pretty easy i think as the wires would only connect one way although I only had 2 wires and some pictures I've seen people have 3 wires? I think the big one to work out now is which one is the chassis earth, which one earths onto the head, and should I have an earth strap somewhere for engine to chassis?