yum install lamp

rpm --import http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

Apache

yum install httpd httpd-devel
etc/init.d/httpd start
chkconfig httpd on

MySQL

yum install mysql mysql-sever mysql-devel
/etc/init.d/mysqld start
chkconfig mysqld on

PHP

yum install php php-mysql php-gd php-mbstring php-mcrypt php-devel php-xml

service httpd restart

vim /var/www/html/index.php

<?php
phpinfo();
?>