Can't figure out how to get to X startup script...

["Krieger, Frank" <FKrieger hitchhiker nmu edu>]

This is my first time using Linux, and I'm trying to get the Gnome to
run.
 
I'm using RedHat 5.2 and managed to get Gnome loaded onto the system,
but for the life of me I cannot figure out how to edit my X startup
script. 
 
How do I get to it, and open it?
 
Please if you could make the instructions simple...(Never used command
lines...)
 
Thanks,
 
Frank Krieger