Edit: this post was being written while the one above was being posted. Evidently your second hard drive is /dev/sdb and the partition is /dev/sdb1.
If your computer has only IDE disks then the second IDE disk will be accessed as /dev/hdb. I am not familiar with the Red Hat environment so I will tell you how to do this on any Linux system. It will require that you use the command line utilities.
The following procedure will destroy all data on the disk. If you want to preserve the data on the disk you can skip the parts about creating a partition table and about making a file system on the disk partition.
You first see if Linux can detect the hard drive using fdisk. Then you use cfdisk or fdisk to create a partition table. I recommend using cfdisk because it makes a graphic representation of the disk structure. Then you use mkfs to create a file system. Then you use the mount command to connect the file system on the second disk to a directory somewhere in the Linux file structure.
First log on as root.
Next see if Linux detects your second hard disk.
Disk /dev/hda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 1 1094 8787523+ 7 HPFS/NTFS
/dev/hda2 1095 1155 489982+ 82 Linux swap / Solaris
/dev/hda3 * 1156 2249 8787555 83 Linux
Here you can see that Linux only sees one hard disk on my system. If I had a second hard disk then the display would continue listing the partitions of that disk.
Use cfdisk to recreate the partition table on the second IDE disk.
Cfdisk is a lot like the partition utility in the Windows installation software. Delete any partition that is there. Then create a partition. Make it a primary partition. Make the type a Linux partition. Write the partition table to disk. Quit.
Next see if Linux detects your changes by running fdisk -l again.
Now make a file system on the second hard disk using the mkfs utility.
mkfs -t ext3 /dev/hdb1
Now create a mount point. A mount point is a directory. Let's say that you want to mount the partition at /mnt/hdb1.
mount /dev/hdb1 /mnt/hdb1
Note that you only have to create the /mnt/hdb1 directory once. It will not go away unless you delete it.
Now allow your local users to access the disk by changing the ownership and permissions of the mount point with the partition mounted.
chown root:users /mnt/hdb1
chmod g+rwx /mnt/hdb1
You only have to do this one time as well. The permissions and ownership will remain unless you change them.
Now add a line in the file /etc/fstab to tell Linux to mount the partition every time the operating system starts.
cp fstab fstab.original
Now use any editor you like to edit the file /etc/fstab. Add this line to the end of that file.
/dev/hdb1 /mnt/hdb1 auto default 0 0
That should do it.
When I was adding tags to this discussion I found that there is already a mount+howto tag. You might want to search for that tag in the search feature on this web site.