If you have MySQL you will have to set up a database and user, either your
host can do that, or you will have a control panel where you can do it
yourself. Just depends on the host. Once you have that, you can make a
connection to your db using PHP with something like this:
$connection = mysql_connect("localhost", "user", "password");
And then you can query the db with:
$result = mysql_query("SELECT * FROM table", $connection);
Ryan , what kind of information are you passing betwen Flash & PHP? if its a simple contact form you may not need a MySQL DB at all. If your wanting to store info then yes you prob will need a DB.