Pen-testing tutorials

- OWASP Testing Guide v4 Table of Contents

https://www.owasp.org/index.php/OWASP_Testing_Guide_v4_Table_of_Contents

- Web Application Pen-testing Tutorials With Mutillidae

http://www.irongeek.com/i.php?page=videos/web-application-pen-testing-tutorials-with-mutillidae

- Backtrack Tutorials 

http://backtracktutorials.com/

- metasploit unleashed

http://www.offensive-security.com/metasploit-unleashed/Main_Page

- SET (Social Engineering Toolkit)

http://www.social-engineer.org/framework/Computer_Based_Social_Engineering_Tools:_Social_Engineer_Toolkit_(SET)