I thought some folks here might be interested in the just-released Web Writing Style Guide. It was produced by an "unconference" of professors and instructors by a "writing sprint," a sort of ad hoc collaboration project. It turned out well in my opinion, so head over and see if you might learn something.
Who is this style guide for?
Well, to be more specific, it’s for anyone interested in learning more about web writing. It’s not intended to be a general book about writing—we’re focused here on the type of writing people do in social media sites such as blogs, wikis, Twitter, and more. We also have a section about the issues you face when you create web pages, whether on your blog, your wiki, or your own website. We’re tailoring it for college students, so we’re not using terms like “deconstruction” or “hybrid narrative” here. Nor will we tell you much about how to do things with software. Our focus is on the rhetoric of writing on the web—how to write things that people will actually want to read. We had fun writing this, and we hope you'll have fun reading it. Enjoy!