help me root my phones

I have been trying to root my epic 4g and my optimus for weeks. I keep getting a signature error on my epic. I have tried so many different programs and none.seem to work. onmy.optimus it says that I "now have root privledges. service stopped". However, busybox and su bin in not installed. I purchaced busybox pro and superuser as well as downloading the free ones. I dont know what to do

 

the first thing you should be aware of is by modifying / rooting your phone could very well leave you with a brick ( useless dead phone ) and i will not be held responsible
THE RISK IS YOURS

for your epic 4g go here
http://forum.xda-developers.com/showthread.php?t=1076967

there are 2 versions of the optimus i can find you don't state which one you have but both versions are here ( scroll down the page )
http://forum.xda-developers.com/index.php

before you do anything do a lot of reading of the forum and then read some more until you are 100% confident you know what your doing and if you don't understand what you are reading leave well alone