Marketing Profs' B.L.Ochman is now telling people how to improve their blog writing. I'd say that makes it official that blogs are now considered marketing communications. (But you knew that already, right?)
Even if you are not writing for a blog, there are excellent tips here for how to write clear, compelling words that speak to your market. Did you spot the problem with the title of this post? I already broke the "no jargon" rule by using "marcom", instead of marketing communications.
A good read, and it's available with the free subscription. How to Write Compelling Blog Posts.
Another good piece on blog writing is available at Ochman's own blog, here.