Question on Fedora

I’ve setup a workstation running Fedora Core 3 and am using it daily now. It’s been 3 days since I’ve booted in to Windows. I really shouldn’t have to unless I want to work on photos, or do some recording. But I have a question I can’t the answer to.

How do I tell YUM to use the Fedora development branch? Yeah, I like bleeeding edge!

TIA for any assistance!