How to Make Text Look Interesting: Minimalist Web Design
Though this article is a way for Space to sell their new theme, I can attest to the information provided being very useful in-and-of itself. It's a strong overview of the fundamentals of typography and basic rules to follow for strong visual hierarchy and content readability.If you want to learn more about typography, I'd pick up (what is considered) the typographic bible, The Elements of Typography by Robert Bringhurst. While it is largely intended for print, most of the rules and suggestions still apply to the web. Alternatively, some pioneering folks put together a web adaptation of Bringhurt's book, http://webtypography.net/