You need to install TrueType Font support to your X Window System. Please take a look at fonts.themes.org for the fonts, and xfstt or X-TT for the font servers.
If you've a bunch of TrueType fonts from MS Windows, edit the XF86Config file to get the fonts from the font folder. Then just tell KDE to use these new fonts with the font administrator utility.
However, many KDE 1.0 applications use a font dialog that does not use the font list of KDE. But there is a workaround: edit the rc files of the rebellious applications directly.