please help and advice regarding steps to rooting my samsung

view story

http://forum.xda-developers.com – hey everyone, i am new here.. i have recently bought a samsung galaxy s3 GT-i9300 and i've used and installed several apps on it and after some time i've come through several apps that needs root in order to run.. so i think its time to learn how to root it incase i wanna try it soon.. after doing some searching i found out this, i will summarize , 1st, shutdown and reboot using download mode 2nd, after ur in download mode, conect usb and open odin 3rd, in Odin , choose PDA and put the .tar file which by searching i downloaded a "CF-Root-SGS3-v6.3.tar" (Please recomend if this is (HowTos)