|Help On Updating||UserPreferences
Also, you should copy the content of the "wiki-moinmoin/img" directory to your "data/img" directory, there are some new GIFs in it. Next version will feature an update script of some sort that does these things automagically.
When upgrading to a new version, copy at least the help pages ("Help*") to your existing directory. Then check whether you miss any new system pages. In the future, there will be a utility that automates this process.