Sol is in the centre, the +90° direction (towards the top of the screen) is Coreward, the 0° direction (towards the left) is the Spinward direction, and out of the screen is "north" out of the galactic plane.
Is that right? I thought that galactic north was defined like terrestrial north, so that the Galaxy spins anti-clockwise when you look down on it from the north. If out of the screen is northwards, and the axis of rotation is above the top of the screen, then what we see ought to be spinning clockwise about a point above the top of the screen, i.e. to the right.
Remember that Galactic co-ordinates are a left-handed
frame of reference because the X co-ordinate is measured backwards, i.e. towards the core instead of out from it.