If your BIOS supports booting from both drives then install to the MBR of the Red Hat drive and set the BIOS to boot from that drive. If not you have two options, install the bootloader to the MBR of the first drive. This will work, butmake sure you have both an XP/Win98SE and linux boot disk to fix it if red hat does it wrong. You can also add linux to your boot.ini file with help from here
I would install grub or lilo to the MBR of the second drive so you have a place to copy the info from w/ out messing w/ the first drive.
If you boot from the second drive and add windows to the boot loader then grub will load first but selecting windows will transfer power to the ntlder. If you install grub/lilo to the MBR of the main drive then grub will point to the ntldr file and transfer power, if you want to not see the ntldr file edit the boot.ini file to have a timeout of 0 seconds. If you add linux to the boot.ini file then the only boot loader will be ntldr (the grub/lilo will be sitting in the MBR of the second drive but you won't use it). Hope that helped.