All wikipedia articles are sorted into categories. You can see these categories at the bottom of every article.

Try going to an article related to the subject of your class. Scroll to the very end to find a list of categories. Choose one, and you'll see a list of subcategories and related articles.

Scanning through these categories can be a quick way to find interesting articles. And as you skim through an article, you can start to think about what could be added or improved.

Categories also offer a good idea of articles you might want to create. What important topics are missing?

The "Academic disciplines" category is a great place to explore and start brainstorming.