After you've installed your wiki, it's time to configure and customize it. The first thing you probably want to do is adapt the look and feel to your personal preferences or the corparate style guidelines.
Mediawiki's look can easily be cutomized with prefab, downloadable 'skins' or 'themes', and using an existing style that already comes close to what you want and adapt it is a lot easier than developing a skin from scratch, especially in terms of positioning components, behaviour of the navigation elements, etc. So, find a suitable skin to uise as a starting point, eg. here.
install the skin :
Then, customize skin : see Mediawiki FAQ for common modifications (e.g. set Wiki Name, replace Logo, ...). By editing the skin's style sheet(s), in .../wiki/skins/name_of_skin/[main].css, you can set style elements such as fonts, fore- and background colors, modify positioning, replace backgrounds, ...
'crom' looks like a good starting point if you want to create a clean, professional corporate look.Mediawiki provides a mechanism for managing user rights, but these are mainly focused on managing the 'edit' rights. When it comes to viewing pages, there are basiclally only 2 modes of operation: : everyone can read everything, or only registered usesrs can read everything. If you want to keep parts of your docuemntation confidential or otherwise limit the sorts of access different groups of users have to the information, mediawiki won't cut it without hacks and workjourounds. It simply wasn't designed fotr that type of work. dokuwiki is better suited for that type of access control.
Granular (edit) access can be managed by creating namespaces (for content) and groups (for users). By splitting your content in separate nama spaces, you can assign edit rights per namespace. Namespaces are created in LocalSettings.php with something like
$wgExtraNamespaces = array (
100 => "Secret",
101 => "Secret_talk",
102 => "Private",
103 => "Private_talk",
104 => "Public",
105 => "Public_talk"
);
Note that this does not work for read access, at least not in the core mediawiki system. There are some user-maintained extensions that provide this functionality, but users my have lots of ways to circumvent the restrictions (crafted URL's, pulling up content through talk or history pages, ....).
If you anticipate having lots of users with read-only access, it's worth considering a server side cache. The wiki will generate static html pages on the fly and put them in a cache directory. Subseuent read calls to the same page will thus not generate database access or php processing, reducing server load. The cached pages will of course be replaced automatically if the corresponding article has been modified. To implement this, you need to create the cache directory and make it writable by the php or web server user account (www-data), and add the appropriate statements to LocalSettings.php.