Place the second monitor next to your first, install the second video card onto your motherboard and hook it up to the second video card. When all goes well, Windows detects the second video installation and begins a magical expansion of your desktop to cover the additional monitor screen. First, your main screen starts. Suddenly, the wallpaper on your primary screen appears on the second. After you get this to work once, the second screen will boot automatically each time you start up the machine.
Some users find it handy to locate their mail programs, always open, on the right monitor.
Others drag all their icons to one monitor so they can view the Web or work on applications on the other. With large graphics programs, you can drag toolboxes and other clutter to the second screen. They're always out of the way, but still convenient. It's not for the faint of heart. Some breeze right through it.