I've found MSDN to be useful for the latest version of M$ products, but not for older ones. At this point, Office 98, which I use, is "really old" :-)
If you have Visual Basic installed, you can use its Object Browser to help ferret out the details. Create a new project, use Project/References to add the approprate library (Microsoft Word 8, or whatever). Then use the object browser.
The descriptions are not as good as the MSDN docs, when available, and there is no "usage" information, but it will certainly point you in the right direction, and helps immensely when dealing with M$ "upgrades".