Marketing Today

Online guide to marketing in the information age, with a focus on business-to-business marketing. Lots of articles on marketing from this resources site for small businesses.
Revolution Online digital economy magazine targeted primarily at marketers.
PRSA (Public Relations Society of America) Web site of the world's largest organization for public relations professionals. An essential resource from the American Marketing Association, providing relevant marketing information that experienced marketers turn to everyday.

PR Communications

Good blog posts about marketing and PR from John Cass, a Boston-based PR strategist.
All About Public Relations Great resource site with lots of articles on the PR business.
Marketing Magic Another great resource with an archive of hundreds of useful articles and tips on marketing and PR. Free registration required for up-to-the-minute breaking news from this most authoritive source covering the Advertising Industry.
Marketing Vox

Keeping marketers and media professionals informed of important industry news and best practices.

Quirk's Marketing Research Review Online magazine promoting the use, understanding and value of marketing research across all industries.