Here some useful online resources, in case any of you ever feel the same, or are suddenly overcome by a need to fix a dangling or misplaced modifier:
DailyGrammar.com: Check out the archives for a list of topics already covered.
Webgrammar.com: Includes a list of common mistakes. See the Writing Center list of topics for other useful grammar-related information.
Guide To Grammar and Style: By Jack Lynch, whose site has been on the Web for as long as I can remember. Frequently updated.
Common Errors in English: By Paul Brians. "The concept of language errors is a fuzzy one. I’ll leave to linguists the technical definitions. Here we’re concerned only with deviations from the standard use of English as judged by sophisticated users such as professional writers, editors, teachers, and literate executives and personnel officers. The aim of this site is to help you avoid low grades, lost employment opportunities, lost business, and titters of amusement at the way you write or speak."
Good Grammar, Good Style: More than 100 pages of useful articles and frequently asked questions. Search the archive with keywords.
Guide to Grammar and Writing: Includes a useful useful FAQ.
The Slot: This has been one of my favourite grammar sites, though it's not really meant to be a reference site like the ones above. The Slot is a copy editing site by the highly opinionated Bill Walsh. Do check out his Sharp Point columns.
If you know of other useful grammar-related resources, feel free to suggest them below! Please note that I'll be offline for the next while, so will not be able to approve held comments until I get back.