I typically preferred a shared fat32 partition for documents and anything you want to use in both OS's.
What boot loader are you planning on using? If you're going to just use grub, then the 100MB partition should be ext3, not fat32 and then just direct RH to install /boot on that partition and grub to the MBR. If you're using a 3rd party bootloader (SBM, XOSL, etc) then they'll probably tell you what to format that as.
EDIT: @pixellany -- I like to have a separate boot partition on dual boot machines, because then I can nuke the linux install for a different distro and XP will still be able to boot because grub's files are in that /boot partition.
Last edited by pljvaldez; 12-19-2007 at 11:26 AM.