Today I faced the same problem.
Installing this plugin using the register of the plugin does not work (for iOS) at the moment.
You have to clone the repository ( phonegap-facebook-plugin) into the local file system, say $HOME/src/phonegap-facebook-plugin. Then install a plugin pointing to this path, for example.cordova plugin add $HOME/src/phonegap-facebook-plugin
...
, FacebookSDK.framework . :
$ ls -l plugins/com.phonegap.plugins.facebookconnect/platforms/ios/FacebookSDK.framework/
total 24
lrwx
lrwx
lrwx
drwx
... .