http://forum.xda-developers.com/show....php?t=1209988
That forum has a LOT of great info on rooting and all stuff pertaining to custom ROMs, kernels, etc.
As far as benefits go to THAT particular device, I'm not sure. But, in general - Freedom to optimize your device for what you want to use it for. Over-clock for power, tweak for battery life increase, changing themes, removing bloat-ware, etc... However, before you decide to jump into the rooting pool, read the instructions. Then read them again. Then read them another time. Then once more. Then do it step by step.