Typography makes your mind readable, as WebOL have already posted. Jon Tangerine has just published an informative account of Detail in typography by Jost Hochuli. Typotheque presents several views of that interesting small book.
Let’s quote Jon : « It discusses ‘microtypography’ — the fundamentals of legibility; everything from how we read, to analyses of letters, words, lines, linespacing, texture, and the qualities of type. »