Picture Question

I am looking for a way to have a default picture for each category on the home page. So say I have three categories (Baseball, Football, Hockey). I am using a magazine style them, so on the home page it has just a brief overview of the post and also shows a picture. Well i always have to go to “Custom Fields” and type in the path for the picture. I just want to have it so if I post something to the Hockey Category, it will always show the hockey picture next to the post.