So You Want to Create a Font (Part 1, Part 2). For something with a less presumptive title, there’s this, this, this, this, this, or even this, Eric Gill’s An Essay on Typography.
Eric Gill was a print-maker, sculptor, typographer and thinker [pdf]. An artist whose life has had quite a bit of drama associated with it. There is even a new society dedicated to parsing the impacts of his legacy.