During the installation, don't select "GUI login" or "start X automatically" or whatever Mandrake calls it now.
A better way than that, though, is to become root and edit /etc/inittab. Change this line:
to be this instead:
Save and exit, and then either reboot, or /sbin/init 3
Actually, you can /sbin/init 3
as root without editing the inittab file, if you want, but the next time you boot, X will try to load. If something doesn't work right, it's usually possible to fix, as long as you can boot to something other than X. Which is why I tell people to edit the inittab file.