How do edit/add items/folders to the start menu?

[Todd And Margo Chester]

  Hi All,

In 4.6.2, how do I edit and/or add items and folders to the start menu?  Is
there some tool like gnome's "alacarte" menu editor?

Also (need both answered as GUI tools always leave things off), where
do I go to manually edit these items?

Many thanks,
-T