+1 what Nosquid sez....but I would suggest doing a LOT of reading and browsing through these forums on those topics BEFORE you do anything.
If you're at the point where you are comfortable and know what you're about to do and know what to expect, AND know what kind of things can go wrong and what to do or where to go if something does go wrong...then knock yourself out!
It's true that things can go wrong and your phone can get screwed up, but only if you don't follow the directions (to a T!) the fine folks on here have laid out. When you are armed with some knowledge it ends up being real easy to do.
And most importantly, if there is anything you don't understand, ASK! Lot's of peeps on here that are happy to help. Good luck and enjoy! The FASN8 is one of the best pieces of phone hardware going and you'll like - nay, dare I say LOVE? - it WAAAY better once it's debloated.
One last thing: make sure you do a BACKUP after rooting and installing Clockworkmod Recovery and ROM Manager and BEFORE you install any new ROM. You'll be able to sleep at night a bit easier that way.
As stated above make sure to read all of the instructions before you do anything. Everything you need to know is found here on the forums. I went from having a Quadrant score of 840 to 1749 after installing JT's Super Clean and Vodoo Lagfix. Only issue is that my battery life seems to be getting sucked away a lot faster now.
Ok, i guess the thing now is to make sure i am rooted. i used the one click root by diirk. i have a super user icon in my apps now. i'm rooted correct?
To be specific, you have to wait until 2.2 is released and the devs create a ROM from it and release it, THEN you can flash that new ROM. And when that happens, if yer an early adopter, be prepared for a few bugs here and there. Just like anything else, it takes a community to work out all the kinks when something's new.