Have you read the stickies and all the other information on here floating around about rooting?
You'll need to verify your hboot, version, determine which method you'll use, make sure if you do it manually with adb (which i recommend) that all the files you download are the correct ones... There is a one (a couple) click method but if you plan on venturing into the world of rooting with all these new EVO versions coming out and new RUU's and all that then i'd be careful using a one click method. Nothing else in the world of Android is one click, so if you don't know everything you're getting yourself in over your head.
To safely root your phone you'll need to make sure you know what you're doing. Rooting is not 100% safe by default. You're running the risk of ruining your device. You'll have to be aware of other issues that i've read about on here as well, they include damaging the 4G radio and a few other things.
FYI