Add something like this in the header template:
Code:
<!-- logo -->
<a name="top"></a>
<table border="0" width="$stylevar[outertablewidth]" cellpadding="0" cellspacing="0" align="center">
<tr>
<td align="$stylevar[left]"><a href="$vboptions[forumhome].php$session[sessionurl_q]"><img src="$stylevar[titleimage]" border="0" alt="$vboptions[bbtitle]" /></a></td>
<td align="$stylevar[right]">
</td>
</tr>
</table>
<!-- /logo -->
<table border="0" width="100%" cellpadding="0" cellspacing="0" align="center">
<tr>
<td><div style="width: leftsidewidthinpx">
left side
</div>
</td>
<td>
<!-- forum contents -->
<!-- content table -->
$spacer_open
$_phpinclude_output
Then, add at the very bottom of the footer template
Code:
<!-- end forum contents -->
</td>
<td><div style="width: rightsidewidthinpx">
right side
</div>
</td>
</tr>
</table>
That's the basic's which you can play around with.
But you could also go a few other ways. Get vbadvanced and manualy add it to all the forum pages you want (takes some time to do). Or get vbPortal which will automaticaly add a left side (but not right side) to every forum page.