The PHP installation on Redhat based distributions uses PDO rather than
the standard database connections, especially for SQLite.

Take a look at:

http://net.tutsplus.com/tutorials/php/why-you-should-be-using-phps-pdo-for-database-access/

Here's a simple tutorial:
http://www.phpro.org/tutorials/Introduction-to-PHP-PDO.html#4.2

Although harder to understand, here's the official PHP PDO reference pages:
http://www.php.net/manual/en/intro.pdo.php

You do not need a userid/password for sqlite.  Just remember that the
files are being access by the webserver, not by the owner of the file so
they need the appropriate permissions for modification 

chmod o+rw datafile
chmod o+rwx datafolder/

PHP code example,

<?php
try { $dbh = new
      PDO("sqlite:/users/cs/ugrad/someStudent/public_html/sqlite/database.sdb");
    } catch(PDOException e) { } 
?>