David Allen's "Getting Things Done: The Art of Stress-Free Productivity" is a good companion to The Seven Habits. GTD focuses a little more on the geeky mechanics of self-organization/prioritization.
There are two other excellent "self-help" books that should be part of everyone's bookshelf. They are:
* "Getting to Yes" which I think is the greatest book on negotiation. "How to deal" * "Sources of Power" by Gary Kline talks about how people make decisions. "How to decide"
Give me these four books, and a firm place to stand, and I will move the world.
I'm pretty please with the impact I'm having on the world.
My lack of formatting skill makes it look like there are four books instead of two.