Typography in Ten Minutes

Matthew Butterick, in his online book Butterick's Practical Typography:

This is a bold claim, but I stand behind it: 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.)

All it takes is ten min­utes—five min­utes to read these rules once, then five min­utes to read them again.

A short, concise ruleset that can make any website look more professional. So often I come across blogs that would be 10x more readable if they accounted for rules #3 and #4 alone.

If you end up reading through Mr. Butterick's typography guide in its entirety, consider paying him a few bucks (or more) in thanks. He did a wonderful job with it. (Tip: hyperlinks throughout the guide are indicated by prepended diamond symbols.)