You can find your drive by looking at the drive label, for me it was the "Toshiba 1TB", and its device point is /dev/sda1. Take a note of the UUID of the drive you want to mount, as we will use this later. .
Now that you have found the drive you want to mount, we can proceed with creating a directory where this drive will be mounted on to. You can create or use any existing directory, but I would recommend to create one in your /mnt (mount) folder. I will create a folder for my drive called "movies".
sudo mkdir /mnt/movies
Now lets proceed with automating the mounting process. Open fstab file using an editor of your choice, common one being "nano".
sudo nano /etc/fstab
Add the following line to the end of the file, replacing the UUID you have got from blkid command and mount location of the new directory you created.