Inkscape is a vector drawing program, much like Illustrator, but free AND open sourced. This book is very detailed, assuming you know knowing of vector drawing, and possibly of any kind of digital drawing. It starts out very slow, describing what vector graphics actually are, how to install Inkscape, ect. Then it actually allows you to explore the interface by small little projects, such as basic drawing tools, starting to modify objects, using layers, and stylizing text. Towards the end, it starts touching on topics most well experienced vector artists use on a daily basis, or haven't even discovered yet, such as using filters to stylize your objects, different options for stylizing text, and making custom looking text, as well as manipulating nopn-vector images inside of inkscape, and even using the XML editor to directly modify the SVG, which gives you an intro into how shapes are actually stored, which can of course be used by different programs (such as HTML5's `canvas' tag), due to it being an open format for vector graphics.
If you're new to creating art working with a computer, new to vector drawing, or even want to transition from Illustrator to Inkscape, this book will get you from clueless to experienced in no time.