Which module and screen do the [modid=xx] go on?!

I cannot get the module to show at all. I don't know if I am putting the modid in the right place and I have no idea what a 'separator' menu is.
Please help!
Thank you.

I cannot get the module to show at all

edit the module, publish it in an existing template position, assign it on all pages, and it should show.

Nothing to do with Modid here, first publish the module to show it.
Ced