What writing books would you recommend? I've heard that some rules of grammar have changed/are changing--how do we keep up?Much as I personally hate it, grammar rules change over time (ex: lit vs lighted). Even the experts disagree about what is correct grammar and they will argue over something as "simple" as comma placement, each absolutely certain that they are correct and fully supported by other experts. To someone unfamiliar with the history of language and basic grammar rules, it may seem that there are no rules, or that rules can be broken at will.
This is an incorrect assumption. There are rules, and there are acceptable ways to break the rules. Editors know both. We can tell if you're breaking a currently in-vogue rule because you're following a different rule, or if you just don't know what you're doing. Unfortunately, there is no one, generally accepted, definitive grammar rule source book.
I prefer more traditional usage over the modern, but I've argued with many of my colleagues about what is correct, and we can all defend our own stance. You're never going to guess what a particular publisher uses/wants, so don't bother trying. Even if you know what a publisher usually wants, the grammar rules may change slightly depending on the style of book.
The key to grammar is to select a good source book and be consistent. You need to understand enough grammar that you know why you're following (or breaking) a particular rule.
Here's a pretty good list of sources. You're probably safe with the current edition of Chicago Manual of Style (although I don't agree with all of their rules). I like Eats, Shoots and Leaves by Lynn Trus as a punctuation manual. If you're writing LDS, use their Style Guide to Publications.
Now, for writing books in general, there are so many good ones I hardly know where to start. I have about 40 on my shelf that I really love, and almost that many that I'd like to get. Some of my favorites are Julia Cameron's books on writing, Natalie Goldberg and Annie Dillard. I also have a lot of books published by Writer's Digest that are pretty good. The best way to find good books on writing is to just go spend a day at the bookstore and browse. Or ask a writer you know and respect what their favorites qre.
So how about it readers? What are your favorite writing books?