If this is Word 2003 or earlier, you may have an Insert Chart button on the
Standard toolbar (apparently this isn't standard in Word 2003, however). If
not, you can easily add it. But, to get started, use Insert | Object:
Microsoft Graph Chart. The charting applet is very poorly documented, so
you'll have to figure it out mostly by trial and error (with reference to
the applet's own Help).
If you have Word 2007, then you'll find Chart in the Illustrations group on
the Insert tab.