organizing data for indexing, searches, etc.

Gurus
I am trying to teach users (and myself) the best way to store data. There
seem to be a lot of ways that are based on the old file cabinets, and
business practices that do not take into account the power of the modern
desktop, the indexing applications from Microsoft and others, and the meta
data that lies basically unused.
Today's users are the first generation that will be able to document their
entire existence, and it seems that they are trying to do just that. The
trouble is, they are basically saving everything in enormously complicated
structures that are irrelevant to the indexers, and make storing data more
work than it is worth.

I am considering a solution which is a simple structure:

Work Personal
Education
| | |
|
Data Documents Data
Documents

Where Data is any excel, access, etc, and Documents is any word, PDF, etc.

I am looking for a structure that can also be reflected in mail folders. I
need information on how to best use metadata in files, the most efficient
folder structure for searching, and any references on this problem.
Alternative solutions will also be welcomed.

Thanks,

Harry