In grub the partition naming is as follows
The first number in the partition name is the HDD, the second is the partition number within, both starting from zero.
That means that
First HDD, first partition is called hd0,0
First HDD, second partition is called hd0,1
Second HDD, first partition is called hd1,0
Second HDD, second partition is called hd1,1
Assuming that you have your partitions as follows
hd0,1: Shared data
hd1,0: Gentoo boot
hd1,1: Gentoo root
Your grub.conf file should look as follows:
title=Gentoo Linux 2005.0
kernel /kernel-2.6.11-gentoo-r8 root=/dev/ram0 init=/linuxrc ramdisk=8192
Note: Adjust the hdd and partition identifiers acording to your particular partitioning.
To setup grub use the following commands within the grub console (dont' type my comments):
(If your system does not boot at all, use a linux live or rescue CD to start the grub console)
root (hd1,0) # Sets up the location of the grub stage1 file is (usually corresponds to your /boot partition)
setup (hd0) # Installs grub in the first HDD's MBR
Please note that root(hd1,0) DOES NOT point to the linux root partition, but to the partition where your stage1, grub.conf, etc. are installed.