Chris Brogan: Trust Agents: Using the Web to Build Influence, Improve Reputation, and Earn Trust
Reading this now, good stuff as well.
Dan Schawbel: Me 2.0: Build a Powerful Brand to Achieve Career Success
Dan is the Man when it comes to this topic.
Jason Alba: I'm on Facebook--Now What???: How to Get Personal, Business, and Professional Value from Facebook
A great guide to getting the most out of this social networking site.
Jason Alba: I'm on LinkedIn--Now What??? (Second Edition): A Guide to Getting the Most Out of LinkedIn
The quintessential guide to using LinkedIn to assist you in your job search.
Keith Ferrazzi with Tahl Raz: Never Eat Alone
An absoute must read.
Tony Alessandra: The Platinum Rule: Discover the Four Basic Business Personalities and How They Can Lead You to Success
Great for personal relationships too!