Security for social networking website

Question

Possible Duplicate:
What security issues should I look out for in PHP

How to protect my site(social networking) from being hacked?just suggest some methods that are in common?

i am using php for scripting & mysql for database and i am using CodeIgniter(php framework).

if you know some good tutorial or ebooks then provide me some link

-Abhijeet

Answer 1

Here you go: http://www.phpfreaks.com/tutorial/php-security