Your really going to have to give us more information than this about your sytem, and how far along the process you are.
But assuming you have everything set up correctly already, all you need to do is enter the settings tab on Display properties. Click ont he secind monirot and click extend my windows desktop onto this monitor. Then its a simple case of dragging programs off the side (right side by default) of the screen and they will appear on your other screen. Maximising them at this point will make them occupy the whole of the second screen. Some things like games are a little more tricky as often they will only launch on your primary display. Some will stop you from being able to move the cursor onto the second screen and others may actually disable the second screen.
