Simple and easy: You created a map you want to share with other people? Here is the place you can do it. Just contact me and send me the link to the map and some informations about it. I although need some contact info, that I can post with the map (website, email, FB, etc.). Maybe somebody has an interesting add for your map, so it can be send to you.
As for the start, there are no real categories – we will figure that out. I think a good start is using the countries.