1) First, open up terminal, and determine what type of drive format it is:
With a second hard drive, it'll most likely be /dev/sdb1 or something around there. If you've labeled your drive, chances are it'll say LABEL="your label". Note the TYPE="xxxx", which will determine which of the following you'll use. In my example for my secondary hard drive:
/dev/sdb1: LABEL="Storage" UUID="92DEADA8DEAD8557" TYPE="ntfs"
2) Now you'll make your directory for your new mount. I like to keep the name of the folder the same as the drive label, but you can name it whatever you want.
sudo mkdir /media/Storage
3) Man this is so hard. Now open up your fstab...
sudo gedit /etc/fstab
4) And depending on your drive type, follow only the appropriate one:
*NOTE* It doesn't show up correctly here, but there is a tab where every space is. This is important! Copy-paste from here won't give you exactly what you need, so simply delete each space and TAB once.
/deb/drive /media/location type defaults 0 0
Also, make sure you replace "/dev/sdxx" with your drive (such as "/dev/sdb1") and the "/media/xxxxx" with your same directory name you did above (such as "/media/Storage").
/dev/sdxx /media/xxxxx ntfs defaults,umask=007,gid=46 0 0
/dev/sdxx /media/xxxxx vfat umask=0000,uid=1000,gid=1000,auto,rw,users 0 0
/dev/sdxx /media/xxxxx ext3 defaults,noatime 0 2
Note: If you ever remove/comment out this line in /etc/fstab, the drive will be stuck in "read-only" mode.