This can be easily done in 5 steps (to get good):
1) Search for the article name
2) Click on the article name, in red, to start creating it
3) Choose a category. The main options are: Anomaly, Entity, Location, Ritual and General
4) Choose a template, if needed. The main options are: Anomaly, Entity and Location
5) Write the article. Here's a nicely formatted one: