Hi dante -
I am not familiar with RedHat, but they are saying to open the file named 'rc.local' which is in directory /etc/rc.d, or the file '.bashrc' which is in your home directory, add the line as you typed it in the console, and save the file. I don't know which file is the preferable location in RH.
you can use any text editor to do that - maybe kedit, or whatever RH installs - look in the menu under "text editors" or some similar title. you can always use vi, but it can be a bit confusing at first.
to get a listing of your current environment variables, try typing 'env' in a console.