Easiest way to do it is to edit the header and footer for the board.
Depending on the way your boards set up and where you want it to appear you could add this to the end of you header
Quote:
<table width="750" border="0" cellspacing="0" cellpadding="0">
<tr>
<td>
|
To the start of your footer add
Quote:
</td>
<td> Put your banner code in here </td>
</tr>
</table>
|
Been a while since I did this but that should work. You can mess around with widths and alignments of the table and columns.
Hope that helps