How to write a test case for facebook operation?

Hello Everyone,

Good Morning!. I need a clarification for writing testcases for facebook site or any other social networking site. May Know standard testing techniques can apply for this? Such as security testing, Compatibility testing , user authentication and functionality. I request anyone explanation on this scenario. Thanks in Advance...

Regards,

Vikram Venkatesan,

rbv.vikram@gmail.com