This is overly wordy commenting but thats just my thoughts. Here is how I comment:

Code:
 Private Sub frmGame_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Reset
        ResetDisplay()

        'Initialize List
        Numbers = New List(Of Integer)

        'Start Timer
        BingoTimer.Start()

        'Generate Card
        For index = 0 To 41
            CardNumbers(index) = Rand.Next(1, 100)
        Next

        'Images
        imgGridBall(0) = "Images\Ball_1.png"
        imgGridBall(1) = "Images\Ball_2.png"
        imgGridBall(2) = "Images\Ball_3.png"

        'Build Grid
        BuildGrid()
    End Sub