Youtube embed link: https://www.youtube.com/embed/[id_do_video]
Example: https://www.youtube.com/embed/D_E58tNUJRs
And in case you get recent youtube videos use GoogleAPI and collect the feed link from recent / highest rated videos.
Here link has this link that can help you in relation to channel search for channels.
And to add the value to the database (I'll be using mysql in that case, because it's less complicated to work with) use this [php and mysql]:
<?php
// conecta com o servidor
$mysql_conexao = mysql_connect(servidor, usuario, senha);
// prepara o comando
$exec = "INSERT INTO nome_da_tabela (coluna1, coluna2) VALUES (value1, value2)";
// executa e verifica o comando
if($mysql_conexao->query($exec) == TRUE){ //inserido com sucesso! }
?>