As I have been writing my book, I thought to give a list of what books are most helpful to me while writing. I try to limit the books to be general purpose, in that they can apply to non-science writers, and to non-book writing, when possible.
- The Chicago Manual of Style — This is the book for style guidance in general.
- The TeXbook by Donald Knuth — I write in LaTeX, so it naturally helps, but it also presents a strong low-level view of typesetting a book that can be very informative.
- The Elements of Typographic Style by Robert Bringhurst — beautiful book about the beautiful topic of typography. Very nice book on design, fonts, and many other aspects.
- CSS: The Definitive Guide by Eric A. Meyer — If you are designing content for the web, this book is a must.
- Mathematical Writing by Donald Knuth — A good overall book on writing science and mathematics. It's getting harder to find, though, but most of the text is available online for free.
- The Associated Press Stylebook on Briefing on Media Law — If you are writing an article for many online and print media outlets, knowing the AP style manual is a must. The alphabetical organization of this helps find topics fast, but doesn't make for very good topical reading (like Chicago does).
Although not a book, Grammar Girl puts out a podcast that provides many useful tips for writers and editors, to help keep you on your grammatical toes.
Last, but not least, you can just pick up a book that you like and see how it states things. Older books (say, 1960s and before) are often better, since a lot more care often went into their making, but a good solid book by a competent publisher today can also be good, in many cases. Many publishing houses will also post their style manuals and guides on the web for authors to take a look at.