The help system is much improved. Besides the usual options under the Help menu, Office 98 comes with an Office Assistant. The standard one, Max, looks like a Mac Plus with legs. Max is also available for online help. Max then displays options that usually take you to the right place in Office's help system.
Balloon help is well implemented.
You can point to anything on a toolbar, window, or dialog box, and get a concise description of what it is. This is especially useful for the Preferences dialog box, which has several options with cryptic names. In all of the Office 98 applications, URLs are live - you can click on a link in any Office document and your Web browser will launch and display the page. All of the Office applications can save their documents as HTML pages, though with varying degrees of success. Since the release of Office 98, one serious privacy issue has arisen.