Campaign magazine (UK)

Weekly magazine for news and information in the fields of advertising, marketing and media.

The Economist Style Guide (UK)

How to write more proper.

How Stuff Works (USA)

The brainchild of Marshall Brain, it's just what its title implies. It even has an article on How Ad Slogans Work -- I wonder who wrote that?

Kogan Page publishers (UK)

Britain's leading independent book publisher.