For a start your FC5 should call Sata as sda and sdb.
hda is reserved for the IDE disk.
You are right in dumping the LVM. You only need two partitions; one for swap and another one for the root "/" of FC5. IN this arrangement /boot is automatically as a subdirectory to /.
Just go in as an expert, select an partition and edit it for mounting /, select formatting to Ext3 and click OK. FC5 installer will know what to do with the swap if there is one there.
When it comes to the boot loader select Sdb if you don't want XP's MBR in sda to be overwritten. You then use the Bios to switch sdb to boot before sda. Thereafter you will have FC5 but XP should be temporarily out of action.
XP can be booted by editing /boot/grub/menu.lst of FC5, by adding this lines
title My XP originally in 1st boot disk now in 2nd position
map (hd0) (hd1)
map (hd1) (hd0)
Save the file and you XP will become available after a reboot. The two map statements switch the disk order just before XP is booted and revert back automatically to current state on exiting XP.
More details and explanation in the Section A of the second link in my signature. The booting tips Link also have plenty inoframtion relevant to you.