Joel Comm: Twitter Power: How to Dominate Your Market One Tweet at a Time
Good overview of Twitter - nice collection of tips and tricks highlighted.
Paul Gillin: Secrets of Social Media Marketing: How to Use Online Conversations and Customer Communities to Turbo-Charge Your Business!
Good overview of how customer service and social media interact with each other, as well as a good general overview of social media.
David Meerman Scott: The New Rules of Marketing and PR: How to Use News Releases, Blogs, Podcasting, Viral Marketing and Online Media to Reach Buyers Directly
A great overview of many new social media tools available for both small and large businesses. Strategic, practical, in-depth.
Denis J. Hauptly: Something Really New: Three Simple Steps to Creating Truly Innovative Products
Hauptly's book focuses strongly on the concept of product innovation, but this is still a good overview of the process of innovation. Practical, but also inspiring.
Tim Hurson: Think Better: An Innovator's Guide to Productive Thinking
One of my favorite things to do in the world is to facilitate brainstorming sessions. You never know how the collective power of the group will function...and the results are always interesting, and usually powerful. This is a great guide to making those brainstorming sessions more useful, and more productive.