pentest network and systems

Dear

i need your help, i would like to make audit in our Network, and i wish to do pen test on some server windows and unix or linux OS and other equipements like Cisco Router and switch

could you please help what i can do that ? i know i can use Nmap for test port and nessus for unix but is there any other tools like LANGFI ? what is the free tool can help me to do auditing for our Cisco swhtch and router ?
and anyone can let me know how i can use metsploit for get system linux or hpunix without root user ?

Best Regard & thank you advance

Just stick with Nessus. You are obviously nowhere near qualified to do a penetration test, so a vulnerability/risk assessment is all you should do.

Trying to learn to perform security testing by playing around with Backtrack is fine, but you shouldn't be doing it professionally until you are much more experienced. As a hint, if you have to ask "How do I perform a penetration test", in those or similar words, you are not ready to do it. Nor are you ready if you don't know what to do after running nmap to identify open ports. There is more to it than just learning how to use Metasploit and following a few tutorials.

Trying to perform Penetration Testing with only basic computer knowledge is like trying to do someones taxes after only learning basic addition, or like trying a court case after watching an episode of Matlock.