Here are links to some communication resources that may be helpful for you, sorted by topic area:
Apoplectic Apostrophes – a blog by editor Suzanne Purkis, who writes creatively about grammar topics.
Grammar Girl – Grammar Girl answers grammar questions in a thoughtful and fun way.
Grammar Girl’s Quick and Dirty Tips for Better Writing by Mignon Fogarty
Grammar Grater – A series of short podcasts by Minnesota Public Radio, featuring Luke Taylor and the Grammatis Personae Players™.
Purdue Online Writing Lab – A great grammar resource from Purdue University.
Beginnings, Middles, and Ends by Nancy Kress – A great guide on dealing with the most troublesome parts of a story.
On Writing Well by William Zinsser – Focused on non-fiction, but applicable to everyone.
Story Engineering by Larry Brooks – A useful resource describing how all the parts of a story should fit together.
The Phone Lady – A fantastic blog about telephone speaking skills.
Public Words – A blog that provides tips on public speaking.
Please feel free to add your own favourite resources in the comments below.