The Resource Graph is a view on its own, but it's best used as the lower pane of a combination view. It shows a bar chart of the allocation of the resources selected in the upper pane, or of the resources assigned to a task that's selected in the upper pane. This makes gauging the extent of a resource's overallocation easier.
Displaying the Resource Graph
Click View, Task Usage.
Click Window, Split to show the lower pane.
The lower pane appears with the Task Form.
Click somewhere in the Task Form.
Click View, Resource Graph to show the Resource Graph.
The name shown is the name of the first resource assigned to the selected task.
The black line shows the Max Units value of the resource.
Red sections show the amount of the overallocation.
Scroll to the right using the scrollbar below the key to view the graph for the next resource assigned to the selected task.
You can now see Sean's graph.
Changing the Graphed Field
Right-click anywhere in the Resource Graph to show the context menu.
The graph defaults to Peak Units.
Choose the desired field to graph. For this example, we will pick Overallocation.
Notice that the graph only shows bars for time periods in which the resource has an overallocation.
The bar shows the number of hours over the Max Units value the resource is for the time period.
Click View, Task Usage. 
Click Window, Split to show the lower pane. 
The lower pane appears with the Task Form. 
Click somewhere in the Task Form. 
Click View, Resource Graph to show the Resource Graph. 
