vb:each question

[Boofo]

I'm trying to figure out the vb:each stuff in the templates and it makes sense in some areas, and so much in others not in others. I have the following query:

$referrals = $db->query_read(" 
    SELECT username, userid 
    FROM " . TABLE_PREFIX . "user 
    WHERE referrerid = '".$userinfo['userid']."' 
        AND usergroupid NOT IN (3,4) 
    ORDER BY username 
    ");

Currently I am using the long-hand way of doing it with the while loop, but I would like to use the vb:each in the template and I can't for the life of me get it to work from a query. Can someone point me to how to set that up properly to use the vb:each?