What is the proper way for doing this? Should I use the expires property in the LiveConnectSession class?
Basically, what I want to do is check if the users is already logged in when I am initializing the user interface.
You would check to see if the LiveConnectSession is nil. The expires property should be used to see if you need to get a new accessToken. But if you are able to read any of these properties, the user is signed in, however the state of their authentication
This page has sample code for signing in a user and checking if a user is signed in: http://msdn.microsoft.com/en-us/library/dn631822.aspx