GNOME Applications menu question

[Maccy]

On Fri, 7 Nov 2008, Matthias Clasen wrote:
> If you want to do it by file editing, you want to look at the .menu
> files in /etc/xdg/menus (they are a bit confusing at first).

Very confusing....is there a quick and easy editing guide somewhere? I 
tried copying an existing file and changing names etc. but no joy.

I would love to do it system-wide.

Mark