How do I Calculate x,y from existing shape geometry using Arcpy?

This seems very easy, but I cannot figure it out. I need to calculate the X-Coordinate and Y-Coordinate to the appropriate fields in my featureclass (XCoord, YCoord). I am trying something like this to no avail:

Maxtbl is set to: r"V:\is\work\mb\Util\MaximoMobile\geodb\TestSnappingSigns.gdb\MaximoSigns_Test" (my feature class).

The shape properties/methods don't seem to be documented very well--where do I find those?