Is there a guide on making custom items?

[Dirk Cutlass]

Is there a guide on making custom items? I was playing around with the toolset and wanted to make a custom weapon (a new baseitem type). Are there any guides to this?

When doing this, can I develop it all in the override directory, or do I have to stick it in a hak to make it work. (I know it should go in a hak eventually, just talking about developing locally for now).

How can I edit graphics, I got a free gmax tool, but it doesn't seem to recognise NWN mdl files.

Anyother tips / advice?