Installing Gcard

[littlejumbo]

Hello Everybody,
This is Lj and I am very much curious to try gcard (a free ecards script) but having trouble installing the script. If anyone of you have ever used gcard or know how to install gcard, please help me install the script.
I've uploaded the files into a folder called ecards in public_html
and i've changed the sitePath in config.php to
$sitePath = "http://www.littlejumbo.co.cc/ecards"; // needed to create url for eCard pickup.
I've created a new database in MySQL called ecards and have changed some info in config.php as follows:

$dbhost = 'localhost'; // database host
$dbuser = 'my new db'; // database user name
$dbpass = '*******'; // database user password
$dbdatabase = 'ecards'; // database with eCards tables

I am not sure what to fill in the place of localhost or should I just leave it like that?

$imageLibrary = 'GD'; // Choose GD or GD2 - use GD2 if it is available

I just don't know what is GD.
Now the harder part for me. I have no clue what is SMTP and dont know what to fill in the following config_email.php.
I would use my site mail from google apps for notification of new ecard to the recipient. I have not create any webmail in my cpanel yet. So, please help me fill the following scripts.

<?
require("inc/phpmailer/class.phpmailer.php");

class emailer extends phpmailer {
// Set default variables for all new emails
var $Mailer = "mail"; // Choose "mail" "smtp" or "sendmail" - "mail" is default
var $PluginDir = "inc/phpmailer/"; // Path to phpmailer directory including trailing slash

// SMTP Options - fill in if using smtp
var $Host = ""; // example: "smtp1.example.com;smtp2.example.com" for multiple hosts
var $Port = 25; // SMTP port

var $SMTPAuth = true; // whether or not to use SMTP authorization
var $Username = ""; // SMTP username when SMTPAuth = true
var $Password = ""; // SMTP password when SMTPAuth = true
}
?>:nuts::rant2::dunno::eek4::happysad::drool::lockd:

Thank you for investing your time and I would be expecting some help from you guys.

Little Jumbo (Little Elephant)