His • Hers • Its • Yours • Mine • Ours • Theirs • WhoseWhen using a possessive pronoun, there's no need to use an apostrophe. Because of the title of my blog, I see this mistake often. Not that I'm judging--when I'm typing too fast and not paying attention, I often type "me" instead of "my," and I still have to stop and think every time I use who/whom.
So to help me with grammar and usage, there are a few books I always keep on hand:
Merriam-Webster's Collegiate Dictionary: I'm particularly fond of this dictionary as it's specific to American English, is updated often, gives detailed word origins and has plenty of usage variations.
The Associated Press Stylebook and Briefing on Media Law: I have a journalism background, so the AP Stylebook is my constant companion. Some of the rules might seem strange at first, but once you begin to understand that media writing is all about getting to the point in the most direct way, it will become second nature.
MLA Handbook for Writers of Research Papers: Lucky for me, I also have a strong background in academic writing. I learned to love this book and its straightforward guidelines for writing. It's also the best resource for citations ever written.
The Chicago Manual of Style: With not much experience in technical writing, I probably use this one the least often. But with the influx of web-based publishing, this book will become more and more important to professional writers.
When Words Collide: A Media Writer's Guide to Grammar and Style by Lauren Kessler: I don't know what to say about this book other than it's brilliant.
The Elements of Style by William Strunk and E.B. White: This is the definitive grammar and style reference book for journalists. Everything I know about writing for papers I learned from Strunk and White. And thanks to this amazing book I read by White as a kid (Charlotte's Web anyone?) I tend to trust them for my fiction writing as well.
Plain English Handbook by Martyn J. Walsh: I know I'm kicking it old school with this one, but I haven't found another grammar books that is so practical, well organized and easy to understand. This book saved me more times than I can count during high school and college English classes.
Don't depend on Wikipedia to answer all of your grammatical questions--it might help when you're in a bind, but it's not always accurate and clear. Keep in mind that grammar and style rules are constantly changing, so update your reference books often. While sentimental attachment comforts the soul, it won't do much for your writing.