The Basics
Merriam-Webster’s Collegiate Dictionary, 11th ed.
A good thesaurus (Roget's or Synonym Finder)
Microsoft Word spell-check and grammar tools, including readability statistics

Editing, Grammar, Punctuation, and Style
Associated Press Stylebook
Chicago Manual of Style (also online, www.chicagomanualofstyle.org)
Copyeditor’s Handbook, Amy Einsohn

Eats, Shoots & Leaves, Lynne Truss
Elements of Style, William Strunk, Jr. and E. B. White
First Five Pages: A Writer’s Guide To Staying Out of the Rejection Pile, Noah Lukeman

A Grammar Handbook for You and I (Oops, Me!), C. Edward Good
Right, Wrong & Risky, Mark Davidson

Self-Editing for Fiction Writers: How to Edit Yourself into Print, Renni Browne and Dave King
Sister Bernadette’s Barking Dog: The Quirky History and Lost Art of Diagramming Sentences, Kitty Burns Florey

Writing
A Writer’s Guide to Fiction, Elizabeth Lyon
On Writing Well, 30th Anniversary Edition: The Classic Guide to Writing Nonfiction, William Zinsser
On Writing: 10th Anniversary Edition: A Memoir of the Craft, Stephen King
Art and Craft of Writing Historical Fiction, James Alexander Thom
Writer’s Digest books, www.writersdigest.com
Writer’s Market
Writing Down the Bones, Natalie Goldberg

Writing the Memoir: From Truth to Art, Judith Barrington

Recommended resources