SEO News: Massive Article Marketing Campaigns for Link Building STILL a Bad Idea
A reminder from Google about links in large-scale article campaigns
Guest blog articles, partner posts and other contributor content are good "when they inform users, educate another site’s audience or bring awareness to your cause or company. However, what does violate Google's guidelines on link schemes is when the main intent is to build links in a large-scale way back to the author’s site."

Examples of things not to do are on Google's Webmaster Blog:
Shared publicly