
This is the only book that describes a complete approach to customer-centered design, from customer data to system design. Readers will be able to develop the work models that represent all aspects of customer work practices.
For teasing apart complex workflows I'd suggest Holtzblatt and Beyer's Contextual Design book, I taught a user-centered research and design class many years ago and used that as our textbook, hopefully it still holds up.
For organizing complex applications I like to start with affinity diagrams, card sorts, and collaborative whiteboard sessions. And of course once you have a working prototype, spend as much time as possible quietly watching people interact with your software.
a. About Face 3 by Alan Cooper
b. Contextual Design by Karen Holtzblatt
These two will set you up.
2. [Emotional Design: Why We Love (or Hate) Everyday Things](http://www.amazon.com/exec/obidos/tg/detail/-/0465051359/) by Don Norman
3. [The Elements of Typographic Style](http://www.amazon.com/Elements-Typographic-Style-Robert-Brin...) by Robert Bringhurst
4. [Grid Systems](http://www.amazon.com/Systems-Graphic-Systeme-Visuele-Gestal...) by Josef Muller-Brockmann
5. [Ordering Disorder: Grid Principles for Web Design](http://www.amazon.com/Ordering-Disorder-Principles-Design-Vo...) by Khoi Vinh
6. [Why Customers Really Buy: Uncovering the Emotional Triggers That Drive Sales](http://www.amazon.com/Why-Customers-Really-Buy-Uncovering/dp...) by Linda Goodman (I've had the pleasure of meeting her and overhearing her office conversation during my daily tasks at the office in Houston, where she worked for a spell. Incredibly sharp, and it is clear that her principles exposed in this book are thorough-going in her interactions with people. I think it would be important to apply her research to Lean methodologies, building Features only around Emotional Triggers. This is what we are aiming at, but I am making this connection right now, I believe, in saying this.)
7. [Contextual Design: Defining Customer-Centered Systems](http://www.amazon.com/Contextual-Design-Customer-Centered-In...) by Hugh Beyer, Karen Holtzblatt
The Design of Everyday Things (http://www.amazon.com/Design-Everyday-Things-Donald-Norman/d...)
The Humane Interface (http://www.amazon.com/Humane-Interface-Directions-Designing-...)
Contextual Design (http://www.amazon.com/Contextual-Design-Customer-Centered-In...)
Favorite UX books
The Design of Everyday Things
The Humane Interface
Contextual Design