[natnatenathan]

I came here to say this. I studied art in school (but not an art school, so I'm not very good :) but this book was really the core of the curriculum. The exercises and approach radically helped me improved my drawing. The other component is just practicing a lot. I can't remember the URL, but there was a developer I used to follow who could not draw at all and just committed to drawing every day (using similar exercises). Over the years, he got really good.