A good way to start using query plans is to set the QUERY_PLAN_AS_HTML option ON. This option places a graphical version of the query plan in the same directory as the .iqmsg file. You can view this file in most Web browsers.
In the HTML query plan, each node in the tree is a hyperlink to the details. Each box is hyperlinked to the tree above. You can click on any node to navigate quickly through the plan.