Dual monitor on Linux - Gnome (Debian 5)

Hi, I am trying to setup dual monitor on Linux, Gnome. I don't know how to modify the xorg.conf.
Below is my xorg.conf file. I've read a post and someone asked for the lspci output. Here is the only thing related about the video card:
"01:00.0 VGA compatible controller: nVidia Corporation GeForce 8800 GTS 512 (rev a2)".
By default Linux clones the desktop an both displays. I have 2 identical 19" LG LCDs.
I tried a few things I've found on the internet but I only mess up the screen, I've looked in the man xorg.conf, but is too complicated for me, don't know what to choose and what to setup from there.

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "XkbRules"      "xorg"
        Option          "XkbModel"      "pc104"
        Option          "XkbLayout"     "us"
EndSection
 
Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
EndSection
 
Section "Device"
        Identifier      "Configured Video Device"
EndSection
 
Section "Monitor"
        Identifier      "Configured Monitor"
EndSection
 
Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
EndSection

Select allOpen in new window