Not being a Designer it's tough for me to gauge how well this book presents the challenge of Designing a Drupal website. However, reading about the Designer role was very interesting and I certainly appreciate the effort to start from the User Experience. These computers in front of us need to be friendly to people, and there is a lot of human factors to making a website appealing to humans, of course.
Nordin wrote this book in the first person, and it feels like she's sitting right next to you explaining things directly. This is refreshing from most technical books that put the writer standing behind a podium giving a lecture. Another feature is that scattered throughout the book are interviews with other Designers. Both aspects of the book give you reams of direct honest advice from people who've been in the thick of designing Drupal-based websites.
For example, in Chapter 3 Nordin told us a story of how her first Drupal project went astray because of her initial approach to the project. It wasn't until well into the project, when she started getting content from the client, that she realized the Design was all wrong.
The last part of Planning and Managing Drupal Projects are several useful worksheets to define the consulting/contracting arrangement between the Designer and their Client. Each part of these worksheets is carefully annotated so you understand how to write a Work Agreement, Project Proposal, Statement of Work, etc.
If it's important to you - Nordin doesn't describe any kind of Agile development process.
In all the book is full of helpful advice, based on experience gained in working on real projects. However, because it's so heavily focused on Designers it may not be helpful for non-designers.
You can buy it via this Affiliate Link: Planning and Managing Drupal Projects or via O'Reilly's website Planning and Managing Drupal Projects: Drupal for Designers, By Dani Nordin