I'm in the process of building a 3D printer and have all the stepper motors wired up and the controller connected to the computer running pronterface.

I can move each axis and also send g-code to the printer.

Now how can I define the current position to be the 0/0/0 position?
I'd like to move the printer into a position where I think should be the zero position and define it as such in pronterface somehow.