This a beautiful handy little book... One of those basic guides of "Though shall do, though shall not" commandments you may tend to dismiss based on its sheer straightforwardness, but that once overcame the initial moment of pride and prejudice spurred by poorly-masked insecurity, you may actually enjoy with its clarity of opinion and point-of-view.
Typography is indeed fraught with opinion. The practice has literally millennia of refinement and polishing, and is one of those creative endeavors so tightly wound around one specific aspect of human evolution (codified communication), that you can actually denounce what is wrong without feeling like an old conservative geezer. Yes, there is such a thing as typographical sins. Yes, it is very easy to tell apart good from bad. It is NOT just a matter of taste. A distorted, badly selected, badly implemented typeface can be suffered from a mile away. You either know it, or you don't.
... This book will help you a bit to be among those "in the know". 44 bits in fact. 22 on what not-to-do, 22 on what-to-do. Simple and to the point. Useful refresher for those of us that are not typographers. (Yes! Even graphic designers have no right to claim understanding of such specific craft). Overcome your hubris and take upon this book for a few hours (that is all it takes), do overlook its badly translation from original Spanish (Is got typos! The irony) and actually learn a thing of two on aspects you probably suspected, but needed validation anyway. Afterwards, do yourself a favor: Go to [...] and learn them by heart. You may now feel entitled to know what you are talking about.