I have made few suggestions on books on writing in my Philosophy of Science class. Here are the links of those books.
"The Elements of Style (4th Edition)" (William Strunk, E. B. White) - This is a classic.
"Publication Manual of the American Psychological Association, Sixth Edition" (American Psychological Association (APA)) - A must-have as a technical guide for formatting, style, and conventions for journal articles.
"The Book on Writing: The Ultimate Guide to Writing Well" (Paula LaRocque) - It is written for fiction writers. Yet, I found it helpful.
"Writing for Social Scientists: How to Start and Finish Your Thesis, Book, or Article: Second Edition (Chicago Guides to Writing, Editing, and Publishing)" (Howard S. Becker) - It is a fun book to read. When you don't want to write or feel like you can't write, read this book. It might get you going again.
"Death Sentences : How Cliches, Weasel Words and Management-Speak Are Strangling Public Language" (Don Watson) - I would like to assign this book as a required reading for MBA students. This book shows how business lanugage filled with empty words and hollow jargons erode our ability to think and communicate ideas. "At the end of the day, the bottom line is it is what it is."
"Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation" (Lynne Truss) - It does not need an explanation.
"Woe is I: The Grammarphobe's Guide to Better English in Plain English, 3rd Edition" (Patricia T. O'Conner) - As non-native speaker, I found this book useful as a guide for English grammar.
"Writing Tools: 50 Essential Strategies for Every Writer" (Roy Peter Clark) - I found this book at a local book store. It is filled with many useful practical suggestions on writing. I particularly like the last section, "Useful Habits."
"If You Want To Write: A Book about Art, Independence and Spirit" (Brenda Ueland) - A generally wonderful book on artistic expression and self-discovery, this affirms that we are all filled with imaginative possibilities.
"How to Read Literature Like a Professor: A Lively and Entertaining Guide to Reading Between the Lines" (Thomas C. Foster) - This is a not a book on writing. Rather, it is a book on reading. But it explains many of the devices that good writers use, which can be useful tools for writers who want to write.