On the left side of the project window is the treelist. Treelist is very useful in organizing your tasks. The treelist is a table of the tasks in the order they are to be completed. It also allows you to group like tasks under headings. How you organize groups and tasks in the Treelist, organizes them in the Gantt Chart.
You can see two types of lines in the treelist, Groups and Tasks.
Right-clicking anywhere in the Treelist will bring up the context menu.
Click here for a full description of the Treelist context Menu and all of its functions.