You can use Rob Bovey's XY Chart Labeler to add labels. It's a free
add-in that you can download from his web site:

       http://www.appspro.com/Utilities/ChartLabeler.htm

In addition to the chart labeler that Deborah noted, you can also use this
macro if for some reason you don't want/need to install an add-in:

Sub AddLabels()               
   Dim RngLabels As Range               
   Dim Ser As Series               
   Dim i As Long               
   If TypeName(Selection) = "Series" Then               
       Set Ser = Selection               
       Set RngLabels = Application.InputBox(prompt:="Select the label
range:", Type:=8)               
       Ser.HasDataLabels = True               
       For i = 1 To Ser.Points.Count               
           Ser.Points(i).DataLabel.Text = RngLabels(i)           
       Next i               
   Else               
       MsgBox "Select a series in a chart."               
   End If               
End Sub               
               
Add the macro to a standard module.  Select the chart and then run the
macro.  In the dialog box, add the reference to the data source like
"Sheet1!A1:A5".               
----
Regards,
John Mansfield
http://www.pdbook.com