Swipe your hand across the screen from left to right

You can restrict certain permissions from apps such as 3G(only use Wifi), block apps from collecting Phone ID,access call logs/sms ,etc only through certain programs like LBE Privacy Guard or Avast Anti Virus which require root for such features

Other features of root is to use programmes such as Voltage smth or SetCPU which can cap your phone processor to like 0.8GHz to save battery,etc.

Root is also required for installing custom firmwares like CM9,etc

to make it simple, root is to give you more administrative access into the core android functions

why root? explained above. but there's more as you learn

how to root? you can follow this guide by androidnz

http://www.androidnz.net/2012/06/at-your-o...-root-your.html

or from LYN user benny888 aka uncle benny

http://leemn.wordpress.com/2012/06/03/gala...rkmod-recovery/

but note that your warranty may be tampered.