Self-Documenting Cubes in Excel PivotTables
If I were the supreme leader of the Excel team (and I've had trouble convincing them of that), one of the first things I would do is add tooltips in the PivotTable field list so that when you mouse over a field, it would describe that field. I've asked for that feature, but so far, it doesn't look like it will make Excel 2010.
So... plan B. But let me first give some background on self-documenting cubes.