It seems that all of the initial Google results for \"using subversion with xcode\" are actually just tutorials for installing and configuring svn and Xcode, as opposed to a
if you want to work with svn through a gui interface then i suggest you use eclipse + subclipse plugin (which have more features and much more reliable and easy than svn on xcode)..
you will work in xcode as normal but you will use eclipse only as an svn client (by creating a general project in eclipse and make it points to your xcode project directory )
and here is a tutorial of how to install subclipse