I can't get Spotlight to search for any documents.
When I search the Finder for documents, nothing happens and the Spotlight search through the menu bar only shows up web searches.
Go to System Preferences. Click on Spotlight. Click on Privacy tab. Click "+" to add a privacy location. Select "Macintosh HD" (or whatever you have named your hard drive).
Wait a few minutes and enter System Preferences again. Go to the Spotlight Privacy tab. Select "Macintosh HD" from the privacy list and remove it.
This is a simple way to force Spotlight to re-index your system.