Designing By Drawing
A Practical Guide To Creating Usable Interactive Design (B&W Version)
This book can be downloaded and read in iBooks on your Mac or iOS device.
This is a book for designers, prospective designers or other usability professionals who find themselves designing interactive systems of any sort. If you are unsure how to proceed with your design work, dread the part of your job where you have to specify designs or just have problems communicating your design with clients or implementation teams, this will provide you with a series of procedures, methodologies and tactics to help.