Use databases to find articles. You can search a database by key words, by author, by journal name, and many other ways depending on where you are starting and what you need to find.
Understanding search strategies for databases can also assist in finding articles.
Google Scholar may also be useful for your research (search box on the left). The advantage is that it is extremely broad and interdisciplinary. The disadvantage is that the results can be chaotic and hard to control. Think of Google Scholar not as a replacement for but rather a complement to the libraries' databases.
There are many other library databases that might be of use depending on the focus of your topic. If you are looking at issues related to education, literature, history, or government policy aspects, for instance, you will want to take a look at other subject areas. All of these categories have their own specialized, core databases, which an be located at the "Databases by Subject" page.