ART (Scott) was an original founder of Plesk before the SWSoft buy out. I believe that Plesk uses some of his stuff in their product. All of his packages are Plesk aware and friendly, as long as you stay away from his 'Testing' repository (use at your own risk).
He basically only supports RedHat type OS's (so no BSD, Debian, etc)
You also don't want to just willy-nilly mix his stuff with just any other stuff found out on the net (not just ARTs stuff, good policy in general). I don't know what SWSoft's 'official' stance is, he is still highly respected by them.
Are you really stuck on using FC4 at this time? What about using CentOS 4 which I believe is currently supported?
Since this will be your first Plesk install, you can certainly do an 'out of box' install and play with it to get familiarized. I highly recommend that you have a 2nd server to use for testing.
What I generally do is:
1. Fresh OS install
2. Install yum and configure for ART's yum repository channels
3. Do yum update to update everything (sometimes I'll skip this step until #5)
4. Install Plesk using autoinstaller, then test the installation (remove watchdog, remove drweb, remove psa-spamassassin, yum install art's spamassassin, clamav and qmail-scanner, etc)
5. Do yum update to update everything again
6. Test Plesk again, create domain, subdomain, email, ftp, etc.
7. Verify that all other packages (mysql, php, etc) are at version levels I want them to be
8. Test everything again. Once I feel 'good' then I'll put the server online and begin using it in production.