The Organized Mind is a cross between a popular science book and a self-help book. The first part explains what neuroscience has learned about how the brain works, which is quite a lot in the last 20 years or so. Most of the rest of the book then suggests ways to use the brain's strengths and to compensate for its flaws to stay organized in our information-overloaded lives.
The main thrust is that we should use external systems as much as possible to supplement our somewhat inaccurate and inefficient memory. This includes things like having to-do lists (preferably on 3x5 index cards so you can re-organize and re-prioritize tasks easily), always storing things in the same place so you don't lose them, using electronic calendars or phones to remind yourself of things you need to know or do, and (if you're a highly successful person) hiring a personal assistant to take care of organizing your life.
There's also a good section on making good decisions that talks a bit about statistics and probability but manages to stay away from complex math. Levitin does present a nice tabular way to compute probabilities, especially in medical situations, where sometimes the error rate in a diagnostic test is greater than the base rate for the disease the test is trying to detect.
Levitin writes well and with a little bit of humour. He keeps the language easy to understand, although the early sections on brain anatomy and function have a lot of technical jargon that might distress some readers.
For me, I didn't learn much that I hadn't seen in other books, but this is a good introduction to the most recent findings in neuroscience and some practical ways to apply that knowledge. My main problem with self-help books, though, is that if it were as simple as following the instructions in a book to make our lives more organized, few of us would need the book. The fact is, most people won't follow the advice (I know I probably won't), so we'll continue muddling through. What we need is a self-help book on why we ignore self-help books.