Installing the Debian way

  # apt-get install module-assistant nvidia-kernel-common
  # m-a prepare
  # m-a auto-install nvidia
  # apt-get install nvidia-glx

Now update /etc/X11/xorg.conf manually. Finally the nvidia kernel module needs to be loaded:

  # grep -q ^nvidia /etc/modules || echo nvidia >> /etc/modules
  # modprobe nvidia

Rebuilding after kernel updates

  # m-a prepare
  # m-a update
  # m-a auto-install nvidia
  # modprobe nvidia
  # /etc/init.d/gdm restart