Sometime back I read an article by Mark Bollton covering the ins and out of grid design. His manner of explaining the topic was more approachable than my first exposure to the theory;
Josef Muller – Brockmann’s Grid Sytems. While Brockmann’s Grid Sytems is a must have, Boluton’s article was a great refresher on the topic. Shortly after reading this article I stumbled on a little program called Atrise Golden Section which draws out ratio grids atop any application. It’s excellent for UI design or wire framing a project.