I'm not really very experienced with image manipulation. Do you know how to access the multiple pages of the TIFF file? If so then printing multiple pages is simply a case of setting one property in the PrintPage event handler. Assuming that you can access a TIFF page by index it would look something like this:
vb.net Code:
  1. Private pageIndex As Integer = 0
  2.  
  3. Private Sub PrintDocument1_PrintPage(ByVal sender As System.Object, _
  4.                                      ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
  5.     'Get the image to be printed.
  6.     Dim imageToPrint As Image = myTiff.Pages(Me.pageIndex)
  7.  
  8.     'Print the image here.
  9.  
  10.     'Increment the page index.
  11.     Me.pageIndex += 1
  12.  
  13.     'There are no more pages to print if the index has gone beyond the upper bound.
  14.     e.HasMorePages = (Me.pageIndex < myTiff.Pages.Count)
  15.  
  16.     If Not e.HasMorePages Then
  17.         'Reset the page index for the next run.
  18.         Me.pageIndex = 0
  19.     End If
  20. End Sub
Note that that is almost certainly not valid code, but hopefully it illustrates the point.

If you don't know how to get at each page of a TIFF then that's another issue, not really related to printing specifically.