Influence - The Psychology of Persuasion by Cialdini.<p><a href="http://www.amazon.com/Influence-Psychology-Persuasion-Business-Essentials/dp/006124189X/ref=pd_bbs_sr_1?ie=UTF8&#38;s=books&#38;qid=1216856193&#38;sr=8-1" rel="nofollow">http://www.amazon.com/Influence-Psychology-Persuasion-Busine...</a><p>The 22 Immutable Laws of Marketing - Violate Them at Your Own Risk!<p><a href="http://www.amazon.com/22-Immutable-Laws-Marketing-Violate/dp/0887306667/ref=pd_bbs_sr_1?ie=UTF8&#38;s=books&#38;qid=1216858700&#38;sr=1-1" rel="nofollow">http://www.amazon.com/22-Immutable-Laws-Marketing-Violate/dp...</a><p>Don't Make Me Think: A Common Sense Approach to We Usability, by Steve Krug:<p><a href="http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=pd_bbs_sr_1?ie=UTF8&#38;s=books&#38;qid=1216860599&#38;sr=1-1" rel="nofollow">http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/032134...</a><p>Information Architecture for the World Wide Web: Designing Large Scale Web Sites, by Paul Rosenfeld and Peter Morville:<p><a href="http://www.amazon.com/Information-Architecture-World-Wide-Web/dp/0596527349/ref=pd_bbs_sr_1?ie=UTF8&#38;s=books&#38;qid=1216860826&#38;sr=1-1" rel="nofollow">http://www.amazon.com/Information-Architecture-World-Wide-We...</a><p>Why We Buy: The Science of Shopping, by Paco Underhill<p><a href="http://www.amazon.com/Why-We-Buy-Shopping-Updated-Internet/dp/1416595244/ref=sr_1_1?ie=UTF8&#38;s=books&#38;qid=1264609112&#38;sr=1-1" rel="nofollow">http://www.amazon.com/Why-We-Buy-Shopping-Updated-Internet/d...</a><p>And at least one Jakob Nielsen Usability book.