$wgGroupPermissions['*' ]['read'] = true;
$wgGroupPermissions['*' ]['edit'] = false;
$wgGroupPermissions['*' ]['createaccount'] = false;

The first line allows public reading of pages but changing this to false would mean that only logged on users can read. I have left pages publicly readable and will protect pages as required using the control access feature.

I also tried to change the default logo by uploading a new logo image and adding  the

$wgLogo = ‘/path/to/your/logo.png’;

to the localSettings .php file but I couldn’t get this to work. The new log failed to display. This may be something to do with paths and permissions and I will have another go later. Another approach will be to overwrite the skins/common images/wiki.png with my own logo file but this will need redoing every time I upgrade and is not recommended.