As it stands, you should be able to just select the "upgrade" option from anaconda - presuming that anaconda offers an upgrade from RH9.
However - there is no substitute for backups. Always back up important files before attempting a full OS upgrade. (In fact: backup routinely anyway.)
I have found the upgrade process problematical - especially if there is the slightest deviation from official RH packages on your system. Much heartache is avoided by artful partitioning.
By default, RH9 has three partitions: boot, swap and root. When I did my upgrade from RH9 to FC2, I didn't bother with the upgrade... I backed up averything I wanted to keep. This mostly involved backing up my home directory since I planned to replace the apps with updated version via yum.
Then I completely repartitioned my drives. I added a home partition and a usr partition to be mounted at /home and /usr respectively.
Thus, when I upgraded to FC4, I was able to use the "install" method and tell anaconda to leave the usr and home partitions alone and replace all data everywhere else. This resulted in an error free upgrade.
the home partitions keeps all the user settings and the usr partition keeps apps that I install.
Thus, if you have the default RH9 installation... you are reccommended to do something similar and save yourself trouble in future.
Bear in mind that what you are doing is not anything like upgrading the windows OS - Red Hat Linux and Fedora Core are different operating systems. Fedora Core is not, nor is it intended to be, an upgrade of Red Hat Linux. It is intended to be a completely different project.
You should familiarise yourself with the fedora community (see
www.fedoraforum.org - and may I suggest you go right to FC4 (there are things broken in FC2 and 3 which are fixed in FC4 - most noticably SELinux and USB hotplugging - you'll also save yourself on upgrades to almost everything.) - see
www.mjmwired.net for well-commented example FC2,3,4 installations.
