The Red Hat install CD can be customized to add new packages to the mix or to replace outdated packages with newer ones obtained from the Red Hat updates directory or some other source. This process is delicate, though, and I don't recommend it for novices. I've never tried this, so if you run into problems, I won't be able to offer any advice. Also, it's necessary to be running Linux to do this, so forget it if you've only got Windows installed (unless you want to try recompiling the genhdlist program and all its supporting programs for your platform, and then I can make even fewer guarantees of success than I already have).
The main thing that's necessary to create a custom CD is to run the misc/src/install/genhdlist program from the Red Hat distribution. Note that this file is not under the RedHat directory, and therefore is not something that's necessary to burn a "basic" Red Hat CD. Pass this program the directory that will become the base of the Red Hat CD -- the directory in which the RedHat directory resides. For instance:
./genhdlist /home/rodsmith/rh52
Once you've run genhdlist, check that the base/hdlist file has been updated (check the file's creation time, for instance). If you wish to add new groups of files to be added during the install procedure, you may do so by editing the base/comps file, but you'll have to figure that out by yourself!
One further note: The genhdlist program relies upon specific versions of certain key files, and so the results may not work cross-versions. That is, you may not be able to create a working Red Hat 5.2 install CD using Red Hat 5.1 if you try to modify the files installed by default from the CD.