Mental models are an important part of your practice as it is a means to understand your target audience and understand their ‘root’ concerns/design considerations. Even though this book is written for one specific type of design, it is not difficult at all for you to transpose the understanding to our project.
Reading this will enable you to further understand what is being asked of you in this project. Combine that with some inspirational blog reading (theres links around here somewhere) and you are moving on to the correct path.
This pdf is an excellent guide to a research method firmly grounded in common sense. But don’t let the simplicity of the process detract from the power of the change it can enable. Talking to users in a structured way, analyzing in a collaborative way, and diagramming with clarity can transform the way we approach the design process in this project.
Better start reading then.