Hi and welcome to LQ
Red hat 9 has been end of life for a while now. If you want to stick with Red Hat, go with CentOS - it's built off Red Hat so your knowledge will still be good. You could also check out RUTE
, it will give you a broad understanding. I'd also suggest going to the O'Reilly
website and/or your local Amazon, you'll get a broader range of books and you may save some money.