If you could read only three books on punctuation and grammar, choose a book on traditional grammar, my book on modern punctuation and grammar, and my book on Sequential Phrase Grammar. (If you can read only two books, skip the traditional book, it won't really help your writing.)
Grammar and punctuation could be thought of as something you had to get right (grammatical) by following the rules, then you are done. That's a HORRIBLE way to think of grammar and punctuation.
How I became a grammar geek:
1. I noticed that there were a lot of new things in punctuation and grammar, but no one seemed to be using even half of them. I set out to write a book using all of them. (Emotion Girl).
2. I decided to write a book about all of these new things. Essentially, why you would break the rules. But that becomes a book of new rules. I call it Writer's Grammar -- the punctuation and grammar that writers use in 2016.
3. In doing that, I became aware of another grammar, which I call Sequential Phrase Grammar. It's what English would be if there were no rules about how phrases should be combined. There's nothing to learn, so everyone knows it, writers use it, it's needed to explain what writers do, and it's an exciting way to write.
3a. So I wrote a book about that. Somewhat jokingly, I describe it as the sequel to my book about 2016 grammar.
4. I rewrote one of my books in this new grammar. There are a lot of choices for style, this is just one.