Selecting Fonts & Typefaces
We have all heard of the golden mean (also known as the golden ratio or golden section): the self-replicating page with a proportion of 1:1.618 that is said to be found in everything from the design of ancient Greek architecture to the growth patterns of plants.
Fontularity: Most Popular Fonts by Operating System [Infographic]
UPDATE: Check out The Big Book of Font Combinations on sale now! I recently compiled a list of the 19 most popular fonts according to usage by graphic designers from all over the web. I could have had 100, but I got it down to under 50, and from there whittled it down to just the 19 best fonts.