Hi Kent,
Well, to be honest, I was born into it. My dad started writing books about programming back in 1970, back when I was just a toddler, and back when the only computers were big ole mainframes with punch
cards and tape drives.
Anyhow, I never intended to become a programmer or a technical writer. I studied music in college, but I eventually ended up working for my dad's technical publishing company. I didn't know anything about programming when I first started, but I have learned a lot with every new book, and now I'd say I'm a competent programmer. Some people think that you need to be an expert programmer to start writing a book about programming, but that's not true. The most important part about writing a book is teaching the skills to your reader. And it's OK if you don't know the skills either when you first get started. In fact, sometimes it's helpful to be at a similar level as your reader when you're writing. That way, you don't assume they know things that they don't know. Of course, you need to learn the skills as you go. And, it's often helpful to consult an expert to make sure you aren't overlooking anything or teaching anything incorrectly.
I hope that answers your question. Thanks!
Joel Murach