This is very easy to do. First, as root, you should type mount /dev/hdXY -t ext3 /mnt/directory. You must change X to the correct drive (b for second on primary ide controller, etc) and Y for partition number (1, 2, etc). Also, /mnt/directory must exist and you can change it to anything you like. If your drive mounts properly, then you can edit /etc/fstab. The proper format is device mount point file system type options fs_freq (used for dumping filesystem) and fs_passno (used by fsck). So, you would add /dev/hdb1 /mnt/directory ext3 defaults 1 2 to /etc/fstab and your drive should mount at system boot.