I think that one of the most challenging aspects of teaching grammar is all the specialized vocabulary. Keeping these handy printables posted to refresh memories on the terminology of grammar will help reduce frustration when it's time for students to work on their own.
Look, even if you're a good writer, you may not be the best grammarian. That may not be much of an obstacle for your personal life, but what about when you're expected to teach the concepts that may still be a little fuzzy for you? This is a great resource for just that occasion with some basic techniques and approaches to grammar instruction.
Interactive gammar is the best grammar. This link brings you to a page that lists all the phonograms in the English language (you know, just in case you forget some), and allows you to click on them to hear what they sound like. This is a great source for both grammar lessons and general literacy since it's easy to mispronounce things if we only see them written in a book and not spoken.
Maybe I'm dating myself on this one, but I can't teach conjunctions without the "Conjunction Junction" song getting stuck in my head. Here's a whole playlist of Schoolhouse Rock videos because they were good then and they're still good now.