after following the instruction for installation , you might have notice that Cakephp will require you to load the plugin using cakephp::load('DebugKit') and according to CookBook 2.0 ( I assume you are using 2.0+ )
New for CakePHP 2.0, plugins need to be loaded manually in app/Config/bootstrap.php.
You can either load them one by one or all of them in a single call:
<?phpCakePlugin::loadAll(); // Loads all plugins at onceCakePlugin::load('ContactManager'); //Loads a single plugin
You must put the code in bootstrap.php else the css/js will not get loaded.