If you're requiring students to use library resources for an assignment, consider the following as you design the assignment:
For more ideas, read these articles:
"Assignments: Being Clear About What Matters" by Barbara Fister (in Inside Higher Ed)
"What Happens to Your Research Assignment at the Library?" by Dennis Isbell (in College Teaching)
Jenkins, B. (2007, February). Guidelines for Effective Library Assignments. Retrieved from http://libweb.uoregon.edu/instruct/assignments.html
Queen's University. (2008, October). Designing Research Assignments.