I was given a review copy of this book because I had also successfully navigated the path out of academia over a decade ago and recently completed a job search. I was not paid for this review.
Wow. I wish someone had given me this book when I was writing up my dissertation and job-seeking.
When I broke the news to my PhD advisor that I did not want to pursue academia further, he replied that I was on my own. He clarified that he would have worked the phones to help me land me a post-doc position, but he was completely ignorant about industry and had no contacts.
There are more general job search books, but--until now--none of them address the unique situation of scientists leaving academia for industry. If you have time, I think it is worthwhile to also read the classic, What Color is Your Parachute? (Do the exercises, no matter how cheesy they sound! They will clarify what you want in a job after academia.)
If you want to follow this path, you should spend $2.99 and an evening to read this concise, yet thorough, guide for how to navigate a job search in industry. Take notes with action items (industry term). Then follow up on your action items and chart your progress. You are going to multi-task and learn project management skills during your job search. ;-)
She is completely right about networking. Start practicing it NOW. I followed up a BA in pure math with a PhD in theoretical physics. Those are not practical skills valued in industry*. Whenever I met a fellow math major, I would ask them what they are doing now and how they got there. Were they happy? Challenged? Making financial ends meet?
Not one math major has ever refused to answer my questions and several offered to help me when I was in job search mode. One of them even convinced his manager to offer me a short-term contract job after a fruitless search for an engineer for one of their openings.
I would add that, it is never too early to peruse online job boards to learn what skills are in demand. Do you have them? What skills would you be interested in developing? Can you learn them while performing your PhD research work?
However, I wouldn't advise learning a bunch of different programming languages or APIs du jour. Just learn one or two commonly-used languages really well. Coding tests are administered in multiple languages and you just need to demonstrate deep knowledge in one. Your cover letter should demonstrate and your references can vouch for how quickly you learn.
You don't need to write cover letters while learning the lay of the land. But, I recommend writing outlines of how your skills and experiences would map into job postings that you see. This will help you figure out what kind of jobs fit you, or what kind of skills you need to develop in order to land the kind of job you want. Writing practice will also make the real job search easier. The book does not exaggerate the importance of good spelling, grammar and writing. In industry, effective technical communication is highly valued.
The book mentions joining affinity groups for networking, particularly if you belong to a group underrepresented in STEM. The book lists several, but not Society of Women Engineers (SWE) in particular. You don't have to be an engineer to join SWE. As long as you are in STEM, you will be welcome. Moreover, they are a large and active organization that is always looking for volunteers to help run their outreach efforts to middle and high school girls. Helping out at their events is a great networking opportunity.
The book makes very effective use of how to spin skills picked up in grad school, such as underwater basket weaving. Enjoy this fun video.
* Performing a 10-dimensional symplectic coordinate transformation on stiff equations to make them more "integrable" (amenable to machine integration without diverging from the solution due to machine noise/round-off error), is an obsolete skill in this era of cheap and ubiquitous computers. I've never met anyone in industry who cares about that.