The recent past has seen a resurge of interest in landmarks for heuristic-search planning. Landmarks are subgoals that have to become true at some point during any plan for a given task. They can be used in various ways to assist the search for a plan. This tutorial will give an overview of how landmarks can be identified for a given task and how they may be exploited for planning. In detail, the following topics will be covered: 1. Definitions of landmarks and orderings, including action landmarks.   2. Landmark discovery procedures, including back-chaining from goals, path analysis in domain transition graphs, and forward propagation of information in the planning graph. 3. Methods to exploit landmarks during planning, including as intermediate goals, in the LAMA heuristic, as admissible heuristic, and as problem enrichment via temporal formulas.