I recently run the updates from the Gnome desktop with RH9.

This has updated my Kernel and I now have 2 choices when I boot. Obviously I know how to edit the grub.conf file to get rid of one of the options. What I would like to know is which files can be safely removed for the old kernel. Am I right in saying they are all within /boot

Pretty much. I wouldn't delete them, for the following reasons. One, most modern drives have considerable space, and if you're running low on space, there are better things to delete than that 1+meg file. (Some jpegs are larger than that.)

Second, and more importantly, is having an extra kernel around can be a lifesaver if something goes wrong. (I know, I play around too much.) In this case, if the first kernel doesn't boot, at least you have a second, fairly new kernel to use. If you don't like the "extra" screen popping up when you boot, there's an option to shut it off and boot your preferred kernel, but still leaving the option open for the older one. (In Lilo, you just remove the "prompt" line, but I don't really use grub, sorry.)