This book is a great practical reference for a product manager or someone managing a product management team. It has a lot of best practices (common in many companies now, for instance, interaction designers, personas and usability testing), but also a lot of ideas and suggestions (using high-fidelity prototype instead of a spec. In fact, everyone who has ever written a spec or (much rarer) has read one thinks it is for the most part a waste of time - so why do we keep doing it?).
Highlights:
* What to do when engineering tells you that your platform is about to collapse, and how to prevent this situation.
* Product manager should work with interaction designer to create a prototype and test it with customers a lot (no, seriously, A LOT). This prototype should be a throw-away, not the actual product. Involve and architect in this as well to make sure that the solutions PM and Designer come up with will be implementable.
* Minimal product: the role of the product manager is to figure out the minimal product that the market wants and deliver it (benefit of cost and time for the company and low learning curve for the customer).
* Rapid response team: have a small team that can work on "there is a bug here we need to fix it urgently" without distracting the team that is working on delivering another version of the product.
* Emotional adoption curve: look for users who are angry at something - this is where an opportunity lies if you can fix the thing that annoys them.
* Ideas how to innovate and succeed in large companies
Also, check out Marty's blog at svpg(dot)com, a lot of ideas in the book are discussed there.