It's a toss-up.
First up, there's Word Help. (How do you construct a macro? How do you convert straight quotation marks to curlies in existing text?)
And, of course, contending is the Chicago Manual of Style. There are so many times when (1) what I'm looking for is not in the index location that most reasonable people would expect it to be, and (2) CMS equivocates on rule after rule.
These tools of my trade need some serious sharpening.