Looks like it's trying to tell you that an important line is missing from /etc/fstab (the /proc line in the error messaes). To fix it, since you can't boot into the system, you will have to boot from the installation cd, which will give you a running system from the cd, not the hard disk.
Once booted from cd, log in as root user (you may be in command-line mode. I hope you're comfortable with that).
To be able to fix fstab, you will first need to be able to mount the partition in which RH is installed (not the same as mounting the filesystem at boot). To do that, you will have to edit the running version of fstab (not the installed one).
In case you're not familiar with vim, I'll give you the commands. If you know how to use vim, just skip over these commands.
Press the letter i to enter insert mode.
Scroll to the bottom of the list, and add a line like this:
/dev/hda1 /mnt/redhat ext2 defaults 1 2
where hda1 is the partition in which RH is installed. If your partition is different, supply that number insead.
where /mnt/redhat is the mount you will create, ext2 is the default linux filesystem type. if you're useng ext3 or something else, use that instead.
once that line is entered into the running version of fstab, press the esc key to exit insert mode. to save the changes, press :wq (that's colon w q) to save and exit vim.
next, creat the mount point in the running system (this will disappear when you reboot):
now, you have a place to mount your redhat partition to gain access files for repair.
mount /dev/hda1 (or whatever you put in fstab)
cd /mnt/redhat/etc to get to the fstab on the rh partition (not the running one).
vim fstab (the installed one, not the running one) and look for the /proc line given in the boot error messages. If it isn't there, add it (as you did with the running fstab), then esc :wq to save the repair.
Now, unmount the partition:
remove the install cd from the drive, and reboot. If proc not being in fstab was the only problem, that should fix it.