I recently setup a XP Pro/Fedora Core 3 dual boot. I'm not sure if Fedora can repartition an existing NTFS drive though. Maybe someone else can answer that.
What I did was I wiped my existing HD clean and booted from the XP CD and created 2 partitions, 1 in NTFS and 1 blank. Then I installed XP on the NTFS partition. Next I booted from the FC3 Disc and installed it on the blank partition. Fedora modified the boot sector and I get a menu for XP or FC3 on bootup. This was pretty easy to do, but I'm not sure if you want to wipe clean your existing drive.