To be able to use 2 monitors with a PC, you would firstly need a graphics card that would give you the second display output port. The first one being the motherboard output. It doesn't matter if the output port is VGA, DVI or HDMI. Till the time you have the requisite cable with you and the monitors support them, it should be fine.
To connect both monitors, follow these steps:
1. Connect both the monitors to both the display ports behind the PC cabinet.
2. Switch ON the PC.
3. On the primary display, right click on the empty desktop area and select the option "Screen Resolution".
4. The second display would be recognized by now and would be shown here.
5. Select the 2nd display from the drop down list.
6. Under the head, Multiple Displays, select the option "Extend these displays".
That's about it. You should now be able to see both these monitors display an extended single desktop. You would now be able to move your mouse pointer from one screen to the other. They would now work as a single desktop and would let you move things around.