Very Confused about where to mount my home switches...

I put my Z at the top of the column so I would assume it would home in the + direction.
I put my X at the left side of the table which would home in the + direction
I put my Y in the front (closest to me) and it home in the - direction.

What I would like to know is the left front corner the place to home? and if that is so the when homed the X can only go in the negative direction and the Y only in positive right?