I prefer a high speed serial connection to the normal 9600, we use 115200 of 57600.
Console Redirection in Bios
To see the post messages and access your bios setup screens, enable console redirection in the bios if available
Grub
Modify /boot/grub/grub.conf to enable serial console
Add:
serial --unit=0 --speed=115200
terminal
Add to kernel line:
console=tty0 console=ttyS0,115200n8
Remove:
splashimage
hiddenmenu
Booted System
Start a getty process on ttyS0 at the same speed specified in grub.conf
Add this to /etc/inittab
# serial console
co:2345:respawn:/sbin/agetty ttyS0 115200 vt102
