I teach interaction design at the Rotterdam University of Applied Sciences (Hogeschool Rotterdam). I found this book to be a perfect introduction, collection and practical starting point for icon and pictogram design. This topic is hugely important within the discipline of interaction design, and it is difficult to find broadly-oriented resources. I found this to be one of the best, along with the work of Paul Mijksenaar. Especially useful is section 2, about the nuts and bolts of pictogram concept and design, including grid, format, cultural conventions, abstraction, and environment (where the pictogram will be used).