installing software not using yum
 

I just installed Fedora Core 4.

I deliberately did not install Firefox and OpenOffice from the Fedora CDs as there are new versions of these available from their respective websites.

The Firefox that I found in the repository was earlier than v1.5.

I have the file firefox-1.5.tar.gz on a memory stick and a CD I burnt. I can't get yum to use either. Is there a way I can get yum to use one of them? Otherwise, will I screw up yum if I somehow install firefox directly into /usr myself? If not, how do I do this?

The same goes for OpenOffice file OOo_2.0.1_LinuxIntel_install.tar.gz.

both firefox 1.5 and OOo 2.0.1 are available in yum as it were. i use nrpms repo for gnome and firefox and OOo is in the standard updates-released repo.

you need to realise that yum is nothing more than a fancy wrapper for rpm's and the rpm library. you can't screw up yum unless you specifically break one of yums files. you can easily run into trouble with later rpm's if you install from source and don't clean it up properly.

Actually, Firefox 1.5 is not in the repository; as I recall it was only 1.0.7.

I saw OOo 2.0.1 in the form of many packages. I tried installing as a group, which did not work. But since I have already downloaded the 100MB+ file, I was hoping to use that to install it.

like i said, it's in the nrpms repo.

AFAIK, OpenOffice 2 comes as a set of RPM packages. You should be able to extract the tarball that you downloaded, change into the directory that is created, and run:
Then change into the desktop-integration subdirectory, and run the same command.

You can install Firefox using the binary that you downloaded from mozilla.com. This WILL NOT break the yum, however the rpm database will not know that it is installed. You will be able to use Firefox if you extract it to /usr/local, and make a symbollic link in /usr/bin to /usr/local/firefox/firefox.

I hope this helps, and post back if you have any more questions
--Ian