I'm currently running Windows XP and would like to find out what specific software and/or hardware I would need to run a dual monitor setup?

As far as software goes, you won't need anything else. Windows supports up to ten monitors. The only hardware that is in question is your video card. You will need to check with the video card manufacture to be sure that it supports a dual monitor setup. Additionally, the video card would need to support the specific monitor that you are adding. For instance, a video card may support a dual monitor setup but may be limited to a certain monitor size. Adding a wide-screen monitor may take your current video card out of the equation.