Dans la Doc :
http://book.cakephp.org/2.0/en/models/retrieving-your-data.html
Il faut utiliser la variable order dans ton find.
find(string $type = 'first', array $params = array())
ou le tableau $params
$params = array(
'conditions' => array('Model.field' => $thisValue), //array of conditions
'recursive' => 1, //int
'fields' => array('Model.field1', 'DISTINCT Model.field2'), //array of field names
'order' => array('Model.created', 'Model.field3 DESC'), //string or array defining order
'group' => array('Model.field'), //fields to GROUP BY
'limit' => n, //int
'page' => n, //int
'offset' => n, //int
'callbacks' => true //other possible values are false, 'before', 'after'
)