To redirect the user to a page after login, create a new controller in gii for the page your user will be directed to after s/he logs in. I'll call this controller 'app' here. Gii will automagically create some files for you- one will be /protected/models/AppController.php
In AppController.php, you will have a default public function (method) called actionIndex. The purpose of this default method is to call (render) the /protected/views/app/index.php file (also created by gii for you). index.php is the file your users will see once they log in. That is the file you will want to modify to build your app. Go back to SiteController.php and change the argument of redirect() in the actionLogin() method
if(isset($_POST['LoginForm']))
{
$model->attributes=$_POST['LoginForm'];
// validate user input and redirect to the previous page if valid
if($model->validate() && $model->login())
// since my controller is /protected/controllers/AppController.php
$this->redirect(array('app/index'));
}
This should get you started. (This is essentially my post on the discussion at
the yiiframework site)