I sit in front of three flat screens. It is terrific. I can’t give any advice on them, though. I’m merely a computer user. My husband set them up, and now I don’t know how we ever managed with just one screen... ;-)
In Windows XP (or 2000, or probably Vista) you can just right-click your desktop background and hit “Properties”, then “Settings”.
You’ll see screen “2” (or 3, 4, etc) grayed out. If you click it and check the box marked “Extend my Windows desktop onto this monitor”, it’ll become active.
You can drag the monitor where it is in relation to your primary one so your mouse moves smoothly from one to the other, and drag the screen resolution slider until it looks right.
99% of the time that’s all you need to do.