I don't know how to use this and only stumbled on it and will show you what I found. As you see all of the vertices' are selected and if you go to EDIT POLYGONS and NORMAL'S then VERTEX Normal Edit Tool it will show you which way your normal's, hence I believe faces also, and if you select the rotate tool you can adjust them individually also, I believe.

As I say I just stumbled on this and it may be of use to you.