Heres "A" way to do it.
This will navigate back and forth from google.com and yahoo.com, every 10 seconds after the page is loaded.
Public Class Form1
Private urls() As String = {"http://www.google.com", _
"http://www.yahoo.com"}
Private index As Integer
Private WithEvents navtimer As New Timer
Private Sub Form1_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown
navtimer.Interval = 10000
WebBrowser1.Navigate(urls(index))
index += 1
End Sub
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
lblDone.Text = urls(index - 1)
navtimer.Start()
End Sub
Private Sub navtimer_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles navtimer.Tick
If WebBrowser1.IsBusy Then Exit Sub
If index > UBound(urls) Then index = 0
WebBrowser1.Navigate(urls(index))
index += 1
navtimer.Stop()
End Sub
End Class