Something like this is a fairly simple way:
Private StartX, StartY As Integer
Private Sub Label1_MouseDown(sender As Object, e As MouseEventArgs) Handles Label1.MouseDown
StartX = e.X
StartY = e.Y
End Sub
Private Sub Label1_MouseMove(sender As Object, e As MouseEventArgs) Handles Label1.MouseMove
If e.Button = MouseButtons.Left Then
Label1.Location = New Point(Label1.Location.X + e.X - StartX, Label1.Location.Y + e.Y - StartY)
End If
End Sub