Linux – Need help configuring Apache, MySQL, PHP on Centos Linux

I am new to Linux (CentOS) and have been trying to setup
up this web application https://github.com/craigrodway/printmaster on CentOS for the
last couple hours.

The instruction from the author is a bit vague for a newbie like me:

• Create directory on webserver to store files (configure as virtual
  host or subdir)
• Copy all Print Master files to the folder you just created
• Create a new directory called session where you extracted the files and make it writeable
• Create a new username and database in MySQL
• Import the printmaster.sql file into the new database
• Edit the
  $db line in inc/init.php to reflect your database details Invent your
  own security (.htaccess, integrated Windows authentication…)

I try to follow the instruction from guide in the wiki section but still could not get it to work: https://github.com/craigrodway/printmaster/wiki/Installation-on-Linux

Here is a history of what I did

1. Installed / configured Apache Server following this instruction:
   http://dev.antoinesolutions.com/apache-server (Visited localhost
   in the web browser and saw an Apache Test Page)
2. Installed / configured PHP following this intruction:
   http://dev.antoinesolutions.com/php (Visited localhost/phpinfo in
   the web browser, and there's the phpinfo output. So it works!)
3. Installed / configured MySQL

— FILES —

[root@localhost ~]# cd /tmp
[root@localhost ~]# wget [url]
https://github.com/craigrodway/printmaster/tarball/master[/url] --no-check-certificate
[root@localhost ~]# tar zxvf master
[root@localhost ~]# mv craigrodway-printmaster-af9843d/* /root/Desktop/printmaster/

Created 'session' directory is in the printmaster directory, made it writable

[root@localhost ~]# mkdir session
[root@localhost ~]# chmod 755 session

— DATABASE —

mysql -u root -p

(enter the password for root user)

mysql> CREATE USER 'printers'@'localhost' IDENTIFIED BY 'printersPASS';
Query OK, 0 rows affected (0.00 sec)

mysql> CREATE DATABASE printers;
Query OK, 1 row affected (0.00 sec)

mysql> GRANT ALL PRIVILEGES ON printers.* TO 'printers'@'localhost';
Query OK, 0 rows affected (0.00 sec)

mysql> quit;

— IMPORT SQL FILE —

Import the printmaster.sql as instructed

[root@localhost ~]# mysql -u root -p printers < printmaster.sql

Open init.php and edit the $db line

[root@localhost ~]# vi inc/init.php

Change $db to:

$db = new fDatabase('mysql', 'printers', 'printers', 'printersPASS', 'localhost');

— Now I set up VirtualHost on httpd —
First of all, do I even need to set up virtual host?

Created the file /etc/httpd/conf.d/testprintmaster.conf with the following text:

<VirtualHost *:80>
  DocumentRoot /root/Desktop/printmaster
  ServerName testprintmaster
  ServerAlias [url]www.testprintmaster.com[/url]
</VirtualHost>

Restart Apache

[root@localhost ~]# service httpd restart

— RESULT —

That's it! But when I visit www.testprintmaster.com on firefox, Apache directs it to a search page … WTF!?

I check the syntax check on VirtualHost configuration

[root@localhost ~]# /usr/sbin/httpd -S

VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
_default_:443   localhost.localdoman (/etc/httpd/conf.d/ssl.conf:81)
*:80        is a NameVirtualHost
    default server testprintmaster (/etc/httpd/conf.d/testprintmaster.conf:2)
    port 80 namevhost testprintmaster (/etc/httpd/conf.d/testprintmaster.conf:2)
Syntax OK

What did I do wrong? Any idea?