10 years of offensive security
Top sysadmin commands that are addictive! - Part 1
How to check if there are any errors in the logs while you are connecting to the website. Image Source: <a href="http://nichegamer.com" rel="nofollow">nichegamer.com </a>
There are many OSs on the web and exploits which can provide nice security flows. If you use Backtrack 5 check this out!