There are multiple root tools available here [Only registered and activated users can see links Click here to register]
Download the tools and follow the corresponding instructions.
Try them one at a time to find one that will work for you. Start with Framaroot as many seem to have success with it, and it is a very simple process, too.
If none of them work, proceed to create CWM and root from recovery.
Here is a tutorial for installing CWM if unrooted [Only registered and activated users can see links Click here to register]