This is from the website Thinkingwithtype.com, which is designed as a companion of the typography book Thinking With Type by Ellen Lupton. This lecture covers many topics, such as: the golden section, single column and multi column grids, baseline grids, modular grids and more.
Typography and Grids By ThinkingWithType
You can read the full lecture here: READ
A PDF that contains many great examples of “Grids and Experimental Typography”: Download15