Typography for Lawyers, by Matthew Butterick
There are two things lawyers use daily: a chair and a word processor. Smart lawyers get comfortable with both. For me, adjusting my chair is straightforward. Adjusting my word processor (and my word processing habit) is not.
Butterick helps you make the adjustment from the typewriter rules that you learned in school. As a result, your documents will have predictable style. Your document's style will clearly guide your reader. Will this make your document more persuasive? Yes, with surprisingly little work.
If you are still not sure whether you should buy this book, just spend a little time at the companion website: typographyforlawyers.com. The advantages of the book over the website are three: better guidance for choosing a professional font, more examples of before/after, and word processor specific advice. The only thing missing is CLE credit.
Finally, I spent about 2 hours on the website and 4 hours with the book. This included the time spent modifying my default templates, fiddling with word processor defaults, buying & installing fonts, and incorporating the advice into my workflow. Looking at documents that I create now, I feel great about the return on the time invested.
You can buy this book at Amazon.