Offering up-to-date information and diverse perspectives on issues, online information can be a valuable resource that supplements traditional course materials like textbooks. In this paper, the source types that students' use for a course assignment and the criteria they apply to determine usefulness of the online information are examined. Sixty-five undergraduate students enrolled in a world geography course in fall 2015 were asked to search for 20 sources of online information about recent changes in oil prices and then to rank the sources based on their usefulness for understanding the topic. The findings will provide instructors with insights for guiding students' appropriate use of online information for academic tasks and lifelong learning.