You got it, like he shared above, the newer GPU cards are made for multiple monitors. A few years back two (2) monitors was all you could do with a single, but now 3 or 4 is standard. Mind you, you will not get to play games at multi-monitor high resolutions on high settings with a single GPU though.
If you are looking for office work, or graphic rendering can, but not games. So it really depends on what you are looking to do. The issue with multiple monitors is the resolution, higher resolution requires more power and more VRAM. That is why most 4K games require 6GB VRAM on a single card and/or Crossfire/SLI.
All you would do is plug each monitor into a different display port on the card, then enter the display settings in Windows (assuming you have Windows) and assign how you want the monitors displayed. Extended, duplicate, which is the main monitor, resolutions, etc. If you have ATI Catalyst or Nvidia Gefore, those control applications can help you as well.