Action/Adventure - This one is relatively self-explanatory. If it has action and adventure, it can be included here. Action doesn't necessarily have to mean car chases and gun fights, either. Action can fit all sorts of different genres.
Activity - This one is something that is limited to WdC in many parts. If a person can participate in it, then it is an activity. There are many items that would fall under this automatically - Interactive Stories, Message Boards, Campfire Creatives, Madlibs, Surveys, Word Searches, Crossword Puzzles, etc. They would all classify as activities because they are... yes... activities!
Adult - If the item is meant for an adult audience, then this is the genre for it. It might include some sexual type scenes, or perhaps other adult situations with crimes, gangs, etc. Something that children, specifically, should avoid.
Animal - Having a single animal as a side character in a story wouldn't really mean it should be put in the Animal genre. Is your main character an animal? Does the story revolve around an animal? Are all of the characters animals? That's when it should be put here.
Arts - Your story or article should go here if you talk about the arts - architecture, painting, sculpture, or any of the other new and interesting forms that art is taking, anymore. It could also be an actual form of art submitted to the website via the image file type.
Biographical - If it is about someone's life - a real someone's life, it goes here. As WdC does not have an autobiography section, anything about your life would also go here.
Business - If it has to do with how to run a business, investments, businessmen, a story about a corporate tycoon, etc. That sort of thing might fit in this genre.
Career - Now, this is just my opinion, but this genre seems more technical to me than creative. While there very well might be a fictional story about someone's career, it's more likely to fall toward the non-fiction if someone is writing about career. In fiction, it seems that while the career may be the main drive of a character, it would be unlikely to be the focus of the storyline. Non-fiction, however, would have so many uses for this one! Articles on how to further one's career, advice on how to get a career to begin with, etc. I can see poetry coming from these, though, which completely contradicts my comment about fiction - heh.
Children's - This one is a bit sticky. While I've seen those who place this label on a story because it is about children, that doesn't necessarily make it a children's story. The items within this genre should be appropriate for children - rated G, so to speak, if we were talking movie terms. Something that a child would enjoy, and is written specifically for that age group. Items that are written about children aren't necessarily something that would interest a child - those might be more appropriate in the "Family" genre, depending on the topic at hand.
Comedy - Is it funny? Well, then it can be put here! This is probably one of the most wide categories. Any number of stories, articles, poems, and other items can be put within the comedy genre, and be absolutely perfect for it.
Community - There are all kinds of communities. Online communities, communities we live in, neighborhood communities, work communities, etc. On the web, sometimes even forums are called communities, because it is a place where people with similar interests can get together and communicate, support each other, etc. If you create an item with such an environment, it would go very well here.
Computers - This genre could be technical with jargon focused on technology/computers, or it could have a main character that's a computer, or, or, or... it has a lot of possibilities.
Contest - Please note,
this is not the genre you label your contest entries with. I see it misused as that all the time. There is a genre named "Contest Entry", and that is where your entries should go. This genre should only be for actual contests on the site, that way it makes it easier for those looking for contests to find them. That, of course, or stories/poems/articles about contests.
Contest Entry -
This is where you put those contest entries. It's helpful to label contest entries with this genre because it lets your readers know you catered the item after specific guidelines. (And sometimes those guidelines aren't those we would usually follow, so we are uncomfortable with them or they might be unusual to the story.)
Crime/Gangster - When I think of this genre, I think of The Godfather movies. There's crime, there's gangsters, there's a funny talking boss-dude - it's the epitome of crime/gangster for my own mind.
Cultural - This genre is very interesting to me. When there are cultures different from mine, my first reaction is to learn about them. I love the tales from other cultures, it allows you to know so much about the past belief systems of a culture, or the stories they used to teach their children right from wrong while they were growing up. If it has anything to do with culture, it should go here. Folk tales, stories passed down from generation to generation, or even articles explaining why a certain culture does some things are appropriate here.