Reliable and scholarly resources are typically written with researchers and scholars (like yourself) in mind. They are often written by specialists or experts with credentials, and generally include a list of additional sources at the end. When searching the library catalog or database, you can often limit your results to "peer reviewed" articles, which means that they have been carefully evaluated by other scholars in the field.

Currency might also be a concern, so if you are researching a rapidly-changing topic (such as science or medicine), it is best to look for articles written within the last 5-10 years. If you are unsure about the nature of a resource, don't hesitate to ask your instructor or a librarian.