PSA: Public Service Advertising 
The PSA Research Center is an on-line information resource dedicated to public interest communications and cause marketing. Includes PSA News articles, monographs, evaluation tips, media placement techniques, and case studies.
http://www.psaresearch.com/The Art of Brochures 
Article on writing and structuring a brochure. Links to other marketing articles from Guerilla Tactics weekly.
http://www.gmarketing.com/tactics/weekly_85.html
Presenters University 
Tips, articles, templates, software and courses to improve presentations.
http://www.presentersuniversity.com
Business Writing Tips 
Free newslettter where you will learn and practice getting to the point.
http://www.businesswritingtips.com/
Alexander Communications 
This site offers a free monthly e-newsletter about clear business writing.
http://www.alexcommunications.com/
Alton Miller 
Public relations writing. Examples of press release, media alert, pitch letter and message planner.
http://work.colum.edu/~amiller/altonmiller/
The Care and Feeding of the Press 
How to write a press release, with special emphasis on what you shouldn't do. Compiled by Esther Schindler for NetPress.
http://www.netpress.org/careandfeeding.html
WritingForResults.net 
Guidelines and templates for writing briefing notes, briefing books, memos and letters. A free site.
http://writingforresults.net/