Quite possibly one of the most important books (well, audio book courses) that I've ever read. I've never really thought of myself as a creative person but Gerard Puccio did what I thought was impossible - break creativity down into a science. He broke down creativity into its various components and showed both when and how to use those components. I saw immediate benefits from this course and plan to continue using some of the exercises that he outlined a few times a week to continue building up my creative problem solving skills.
Can not recommend enough.