To centre your logo, the follow will help
[b]AdminCP -> Styles and Templates -> Style Manager[b]
Then select the style you wish to change and find the
header template. In there you should find something similar to the following:
Code:
<!-- logo -->
<a name="top"></a>
<table border="0" width="$stylevar[outertablewidth]" cellpadding="0" cellspacing="0" align="center">
<tr>
<td align="center"><a href="$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 -->
Yours may be slightly different in the sense that you will not have any <center> or center align tags. Just add those in the relevant places.
Hope that helps