This is in the wrong section, and its a simple question that is answered in almost any "rooting" FAQ on the web. I would say try doing a search next time.
Rooting voids your software warranty. If your phone bricks (unlikely, but possible if you cant follow instructions) and can no longer turn on, you're out of luck. Technically nothing is wrong with the phone hardware wise but you can't do anything with a bricked phone.
If you want to go back to stock rom make sure you do a NAND backup right after you root (go read about this, guides are all over the forum) in case you mess up with roms. And as the above ^ stated, its easy to go back to stock rom unrooted (sprint stock rom), just flash that.