The Model: the series
[EDIT: I covered this series in more depth in Leadership Step by Step, so I recommend the book, but the core is here. I use The Model as a part of my life, basically daily.]

Here is The Model—my model for the human emotional system designed for use in leadership, self-awareness, and general purpose professional and personal development—in series form. Click in the table of contents to the left for each page.
I find this Model the most effective and valuable foundation for understanding yourself and others and improving your life.
Why?
A model’s value comes not from its accuracy but how well it serves its purpose, which improves from effective filtering of information. Street maps, for example, are more useful for driving for having less detail than, say, a satellite picture. Subway maps are more useful for their purposes for having yet less detail. For leadership, self-awareness, and general purpose professional and personal development, I find this model has an optimal amount and choice of information.