The best resource on why and how to use grids is: http://www.amazon.com/Systems-Graphic-Systeme-Visuele-Gestaltung/dp/3721201450 http://www.amazon.com/Systems-G

The best resource on why and how to use grids is: http://www.amazon.com/Systems-Graphic-Systeme-Visuele-Gestaltung/dp/3721201450 http://www.amazon.com/Systems-Graphic-Systeme-Visuele-Gestal... It's primarily used as an aid for visual layouts, but it took on the other useful qualities everyone else has listed as the grid frameworks got popular in the web.