If you know the specific article to find, a good starting point is the A-Z Journals List. Search for the title of your journal and if there's full text you can either search for a specific article or browse issues.
When you're looking for articles on a specific topic, you're better off using a subject database like ABI/Inform to search for a topic. Once you have a list of articles you can view the full-text if it's available. If there isn't full-text available in the database you've searched, click on the button to see if there's electronic access to your article. If there is, you can go directly to the article. If the article isn't available there will be links to the ISU library catalog and Interlibrary Loan.