I would like to have canonical copies of the assignments posted here, but so far I haven't had time to edit and prepare them. For now, look at the Harvard CS161 assignments from 2007 and 2009, or maybe here or maybe here or maybe here.
Note: if you are taking a class, use the assignments from your class, not these! These are provided for instructors and for people who want to try learning the material on their own. The assignments for your course may differ in critical ways.