From the window menu select "split"
Select the top pane by clicking in it somewhere. You know it is selected
because the bar on the far left containing the name of the view turns
darker.
Go to the view menu and select any view which has resources - task usage,
resource usage and the resource sheet are probably the most useful.
Select the bottom pane by clicking on it somewhere.
Go to the view menu and select the resource graph view.
Right click on the resource graph area on the right.
From the menu that pops up choose "Format Barstyles"
On the left half of the dialog box that appears (the part marked "Selected
Resources") set the "Show as:" to be anything other than "Don't Show".
Click OK.
Now select resources or tasks with resources in the top pane and the chart
for all of those selected resources will be shown in the bottom pane.