Connecting to a mysql database with php is pretty easy - all that you need to know is the database_server_name (in this example it is localhost), username, password and the database name. Then you simply use the mysql_connect function to connect to the database server and use the @mysql_select_db($database) command to connect to a particular database on the mysql server.
<?
$username = "db_username";
$password = "db_password";
$database = "database_name";
mysql_connect(localhost,$username,$password);
@mysql_select_db($database) or die( "Unable to select database");
?>