The book, "Write Like a Chemist" (by Robinson, SToller, Costanza-Robinson and Jones, many or all of whom are at Northern Arizona U.) is a fantastic resource.  It focuses on analyzing how chemists write journal articles, abstracts, posters, and research proposals.

I haven't used it directly as a required text, but am planning to consult it quite a bit as I assign a paper in an advanced class this spring.  (Clearly, I should write a review for VIPEr.)