Tracking assignments with the resource timeline
Click this button to show or hide the resource allocation graph beneath each resource's timeline. 
The chart shows a timeline of tasks for each resource you select in the outline. If you select no resources, the chart shows all resources' timelines. If the resource is unavailable during some normal working hours, because it has customized working hours, the unavailable times have a background of the Off-hours color (gray by default) as it is set in the Project Colors inspector. 
Below the resources' timelines, an Unassigned timeline shows the tasks which aren't assigned to any resource. You can drag tasks between timelines to change their assignments. 
A blue bar in the load graph represents time when the resource is being used at 100% of its available units. 
A pink bar in the load graph represents time when the resource is being used at over 100% of its available units. You can level the project to clear up such problems. 
You can zoom the timeline the same way you zoom the Gantt chart. Just choose a scale from this menu or drag in the header area. 