Q I recall that each time I have upgraded Microsoft Office, my fonts have ended up in a real mess. How can I best prevent that from happening?
A Over its different versions, Microsoft Office for Mac has put its custom fonts in a range of different locations. Office X did the dirty and put them in the folder reserved for essential system fonts, /System/Library/Fonts, but Office 2004 was a bit better behaved, using /Library/Fonts instead. Office 2008 and 2011 have been the most disciplined, using their own folder at /Library/Fonts/Microsoft.
However there is still no guarantee that when upgrading you will not end up with all sorts of problems, including duplicates. You can use a high-end font manager such as Extensis Suitcase Fusion, or the free bundled Font Book located in your Applications folder.
At the simplest, you could just open Font Book, wait until it locates all the duplicates, then use the Selected Duplicate Fonts and Resolve Duplicate Fonts commands in the Edit menu to let Font Book choose which to disable. You may prefer to step through each, one by one, working out which to keep and then disabling the other(s), although this can get quite tedious. Avoid making manual adjustments to your font folders and trying to use Font Book, which can cause worse chaos.
Updated from the original, which was first published in MacUser volume 27 issue 2, 2011.