The first is the just published Citizen Marketers by Jackie Huba and Ben McConnell. It's a fast, engaging read and extremely well written. In a nutshell, they explain how ordinary citizens are creating media (blogs, podcasts, video, songs, photo) that rival multi-million dollar ad budgets in their ability to affect brands – both negatively and positively.
Two blog entries that explain Web 2.0 and social media
The second is a blog entry by Jeremiah Owyang: 10 Social Media Strategies for Fortune 1000 Corporations
Third is HP Eric Kintz's blog post: Web 2.0 Trends
And of course The Corporate Blogging Book
… if you haven't gotten to it yet. Readers are calling it the best “How-to” on corporate or business blogging.