Get the Whitepaper called Protecting PHP Application From Hacking. Part 1 of 2.
You can download it from the following link: https://packetstormsecurity.com/files/download/88228/Protecting_PHP_applications_from_hacking_1.pdf
Source: https://packetstormsecurity.com/files/88228/Protecting-PHP-Applications-From-Hacking-Part-1.html