The Help namespace (namespace index 12) is empty in new installations of MediaWiki. However, you can fill it with the public domain Help pages available from MediaWiki.org. To do so, follow these steps:
Run update.php to create the necessary tables.
- Go to https://www.mediawiki.org/w/index.php?title=Special:Export&addns&nsindex=12&action=submit and click Export.
- Go to Special:Import on your wiki.
Import the XML file you just downloaded. It will probably take several attempts to get everything imported. If you run into internal server errors, that probably means you timed out; just keep hitting Back and starting the import again. Check Special:RecentChanges on your wiki between import attempts, if you wish, to see what progress you're making; as the import proceeds alphabetically, you should get closer to the end of the alphabet with each import.
Optionally, you may wish to add a Help link on the sidebar. To do this, edit MediaWiki:Sidebar on your wiki and add: