If you don't find a "news and media" category for the topic you're interested in, simply suggest the website to the next higher category. For example if you want to suggest a website about chocolate news, suggest it to Business/Food_and_Related_Products/News_and_Media.
You'll see that there's a category about chocolate, but not about news & media for chocolate, but if you move up 1 category, it's a less specific category, for all food products, and you should suggest the news & media website about chocolate there.
Please note this category is for the B2B side of chocolate making and selling. Sites specifically selling to individuals should be suggested to Shopping/Food/Confectionery/Chocolate/.