"The Double Helix" by Jim Watson
Watson and Crick discovered the double helix, when Watson was a postdoc and Crick was a Ph.D. student.
"Getting What You Came For" by Robert Peters
A very nice career guide for academic life. It is more focused on Ph.D. students, but is helpful for postdocs too.
"Making the Right Moves: A Practical Guide to Scientific Management for Postdocs and New Faculty"
Based on courses held in 2002 and 2005 by the Burroughs Wellcome Fund and HHMI, this book is a collection of practical advice and experiences from seasoned biomedical investigators.