I have many book recommendations for product managers scattered throughout the site. I have tried to consolidate them here for easy reference.
General Business and Management
These are general business books, but they talk to skills that the product manager needs to the job of creating products that build a business.
The Inmates Are Running the Asylum. I believe that Alan Cooper's book is a must read for any product manager involved in a product with a user interface. It may lead to frustration because you don't control the design process, but it wouldn't hurt to pass copies of the book around your organization! I do admit, however, to having a bias. I have had the opportunity to work with Alan and think very highly of his methodologies and insights.
Bringing out the Best in People. I love this book! I actually carry it around in my briefcase and browse it whenever I think about it. For someone like me, who lacks people skills, it is a great reminder of what motivates people and how to keep your team producing their best work.
Fish! Another fun book about people management and motivation. This book is such a quick easy read that the time you spend reading can be an investment returned quickly by just one good idea from the book.
Good to Great. This is a great read. I think it is a "must read" for anyone working to build a successful company. The research that Jim Collins and his team did to write this book is both fascinating and insightful.
Customer Centered Growth. I talk a lot on this site about the importance of getting in touch with and staying in touch with your customers. Richard Whiteley and Diane Hessan go into much greater detail on methods for reaching out to customers. This book is not an easy read, but it is a great reference. Referred to in the chapter on this site about staying in touch with your customers.
Specific Skills or Projects
These books are much more focused on certain projects or skills.
Words That Work: It's Not What You Say, It's What People Hear is a great book by Dr. Frank Luntz. You don't have to like his politics to appreciate his ability to pick words that resonate with the masses. He has some great rules up front that should be applied to every messaging statement that your write. Referred to in the Product Positioning section of this website.
Influence The Psychology of Persuasion. This book fascinated me so much that I read it twice in a row and then bought another copy for a co-worker to read so that we could debate some of our marketing communications (marcom) activities in light of the chapters in the book. Though the book is more relevant to marcom activities than to product marketing, it is interesting just as a person who is on the receiving end of sales and marketing pitches.
The Non-Designer's Design book has been a life-saver to me. The book didn't make me a designer, but it did give me some great basic layout skills that I use all the time. If I had not read this book this site would be all text, centered, and in caps. That is how bad my layout skills were before reading this book. Ok, so my site won't win any awards for design, at least it is readable... If you ever have to format a white paper, write a one-page flyer, or (worst case scenario) layout a datasheet by yourself, don't do it without guidance from this book! Referred to in the Writing a Datasheet section of this site.
The New Positioning is a great book on branding and positioning. It is a great review even for those of us who should know such things (but often forget). I will often review this book every time I go through a positioning exercise. The reference for this book from this site is in the Positioning Exercise
The Survey Research Handbook. Surveys are an important part of market research and it is easy to pop a survey up on a web site today. But if you want to obtain statistically valid information and fully analyze the results, there are a lot of good tips and checklists in this book on how to do it. It was written before the days of web surveys, but most of the information is valid regardless of how the survey is actually delivered. This book is not an easy read, but it is a great reference. Referred to in the chapter on this site about staying in touch with your customers.
I recently revamped my websites, creating a new design using css (cascading style sheets). I couldn't have done it without these two books.
Stylin'with CSS is a wonderful tutorial and reference on how to design style sheets. The book was clearly written by a designer instead of a programmer, so it is very clean, clear, and easy to use.
The Non-Designer's Web Book I am a huge fan of Robin Williams (both the comedian and the author). This is another one of her great books on design and instrumental in creating an attractive, easy to use website.