OK. Next, are you asking how to draw them in SketchUp, or how to use them, in general but with SketchUp as the design tool?
To actually draw the grid in SketchUp would be tedious as SketchUp does poorly with text - so you have to combine lines with leaders or text, typically along the ground plane.
What I've found that works is color coding or simply labeling with a leader a common reference point - such as a post in B1 that acts as the origin (where the grid would start).
When I use the grid in HSB it is another matter - as HSB actually has a parametric grid - complete with labels, spacing, line styles, etc. etc.
For the practical use of the grid - I've used it in several ways - it really comes down to how you label for the shop, production, and raising.
