categories with images

[randomizeddesign]

I want to add 4 images to the categories box in this site http://www.nordicjungle.com/catalog/ they are

Girls-> (27)

Boys (26)

Accessories (50)

Brands->

 

I want to see an image but no text, also I want sub folders, can someone point me to help, I have searched but no luck

 

thanks