When you've decided you want to write a new article
you just have to click on the proper link. In the community section on the overview pages of the site where other articles and such are displayed there is a link that says Write An Article
. The other way is to go to the articles tab and click on the Write an Article
Depending on where you click that button the tags will be prepopulated with various values. If you're on a category, the tags will contain only that category. However, if you're on a product, then the tags will be filled with the category and all the attributes that the product is attached to. You can modify what tags are chosen by clicking on edit tags
and then deselecting tags by clicking on the box, and add tags by typing in the textbox.