How to add avatars to Categories names?

[charm]

Probably I'm not very accurate in the search, but can't find how to add avatars images to categories.
Also, is it possible to assign one directory to two different categories?
Thank you in advance for any help
Vladimir

[Michael P]

While viewing an image, the Admin will see an option "Mkae Index Thumb", clicking on that assignes it as the thumbnail for the category the image belongs to.