VB 2010 Express DataGridView Control - Add Image

I'd like to add a small red triangle (or similar)in a DGV cell corner to indicate addition info exists, that will show either in a ToolTip or Form while the mouse is over that cell.

I've spent a couple of days researching the paint method, and the VisualStyleRenderer but I'm not getting anywhere, and can't find any examples.

Any examples, or help appreciated