[big_youth]

I recommend grabbing a copy of Web Application Hackers Handbook[0] and try hacking vulnerable vm's[1].

I see that your a sysadmin so if network hacking is more you speed I would download Metasploit[2] and start hacking old linux or windows distros.

[0]http://www.amazon.com/The-Web-Application-Hackers-Handbook/d... [1]http://itsecgames.blogspot.com/2013/07/bee-box-hack-and-defa... [2] http://www.metasploit.com/