One of the most useful books in my library (in an earlier edition) ever since a professor used this as the text in a technical/professional writing course. Anyone who needs to do any kind of technical writing, particularly making technical data understandable to higher management or a general audience, would find this book to be a major help.
Actually very handy for tips on presenting technical information in an interesting way. Plus there's an easy and comprehensive grammar addendum that I reference often. Communication is one of the most important aspects of work, regardless of role, and I've relied on this book my entire career to help do it right!