New To Graphics -- Need Help

I found the following code at a sight:

/// <param name="graphicsSurface">Graphics
object on which the cards are to
be drawn.</param>
public void Begin( Graphics graphicsSurface )
{
        this.graphicsSurface = graphicsSurface;
      this.graphicsDC = IntPtr.Zero;
}

Which is in a class

Now from the main form I need to call this function so I
have

cardDrawing.Begin(NOT SURE WHAT TO PUT HERE);
The only place I have been able to find a Graphics object is
in the onPaint
event which of course does help me as I want to Draw in a
button event.

Any help would be greatly appreciated.