Practical Typography:

If you learn and fol­low these five ty­pog­ra­phy rules, you will be a bet­ter ty­pog­ra­ph­er than 95% of pro­fes­sion­al writ­ers and 70% of pro­fes­sion­al de­sign­ers. (The rest of this book will raise you to the 99th per­centile in both categories.)

Man kann nie genug Nachschlagewerke haben.