How to flash the bios for a p7p55d pro

Hello, this is my first gaming rig, I have it put together and everything, it is really hard to get the thing to boot up, trial and error, the fans and lights will run, but no boot on the screen, I have to keep turning it on and off on and off to finally get a boot screen. I've never flashed a bios before, I've tried and failed miserably on this thing, what do I do, should I get somebody else who has done it to do it, I here bad *** could happen if I do it wrong?