I don't know the difference, but I know that the isntaller in Fedora Core 4 is very easy to use. It's all graphical based, I think it is with Red Hat as well though.
The one thing I do not like about Fedora Core 4 is that it's file managment is terrible, scattered and hard to find things. That is a simple problem to remedy though. Although it seems like they also wanted to make Fedora Core and Red Hat a more public enterprise type of thing, much like Windows...I am not a big fan of that.
Anyways, once you find out which you want, we can help you with the Partitions and the installation all we need to know is your system specs.