Your Mac won't explode or spew. But it's still a good idea to read Caution notes carefully. In my humble opinion, the Tips are the best part, the soul of the book. It's best to be at your Mac when you read these. Imagine foam coming out of my mouth.
Rants are usually irreverent or irrelevant and often both.
For Dummies is divided into four logical parts. I suggest you read them in order, but you don't have to if you don't want to. The first part of Part I is Very Basic Training. Everything you need to know to use a Macintosh properly. We'll start out with a rip-roaring tour of System 7.5's more than 50 improvements and enhancements.