Currently I have a working page which lists items from one object.  I am trying to update this to group by two objects.  Details below:

Current APEX class code:

public class projectTracking
{
  private List<Project_Billing_Item__c> projects;
  public List<Project_Billing_Item__c> getProjects()

    {
      projects = [ SELECT Project__c, Name, Employee__c, Description_of_Work__c,   Hours_Worked__c, Date__c 
						FROM Project_Billing_Item__c 
							WHERE Employee__c = :Userinfo.getUserId()  
            ];
			
      return projects;
    }
}

Current VisualFoce code:

<apex:page controller="projectTracking" showHeader="true" renderAs="html">

<apex:sectionHeader title="My Projects" subtitle="{!$User.FirstName} {!$User.LastName}"/>
<p/>

<apex:form >
<apex:pageBlock title="List of current billing items" id="pageBlock">
<apex:pageMessages ></apex:pageMessages>
<apex:pageBlockTable value="{!projects}" var="proj" rendered="{!NOT(ISNULL(projects))}">
<apex:column value="{!proj.Project__c}"></apex:column>
<apex:column value="{!proj.Name}"></apex:column>
<apex:column value="{!proj.Description_of_Work__c}"></apex:column>
<apex:column value="{!proj.Hours_Worked__c}"></apex:column>
<apex:column value="{!proj.Date__c}"></apex:column>
</apex:pageBlockTable>
</apex:pageBlock>
</apex:form>

</apex:page>

Produces the following rendered VisualForce page:

What I am trying to do now is group all the Project Billing Items by Project on the VisualForce page.  Currently I have updated the APEX class with the correct SOQL Query w/ Left Outer Join to group the results accordingly.  APEX class code below:

public class projectTracking
{
  private List<Project_Billing_Item__c> projects;
  public List<Project_Billing_Item__c> getProjects()

    {
      projects = [ SELECT Name, 
					(SELECT Project__c, Name, Employee__c, Description_of_Work__c, Hours_Worked__c, Date__c 
							FROM Project_Billing_Items__r 
									WHERE Employee__c = :Userinfo.getUserId()) 
					FROM Project__c
            ];
			
      return projects;
    }
}

I am not sure where to start with the VisualForce code though.  How do I update that to reference the List which is referencing two custom objects?   Thanks for the help and let me know if I can provide any additional information!