First I had to choose choose a linux distrobution. I had been researching this for a while and after reading lots of posts like this one, I decided on the "cinnamon" release of Mint.
The distrobution file is an ISO image, meaning an image of an installation disk. I used etcher to burn the ISO onto a memory stick. In order to boot from the stick, I needed to inset the memory stick and reboot my computer. During reboot, I entered the BIOS to set the boot order. (If you don't know how to do this, search the internet for "set boot order in BIOS" and include the model of your computer.)
After booting from the memory stick, I could play with Mint, but there was a link on the desk top for installation. I attached my external drive and ran the installation.
There were a couple of things that required me to do a bit of research. Primarily, I had to decide on a disk partitioning scheme. I opted for a 10GB swap space, a 20 GB partition of the OS (mounted as "/") and the remainder of my disk in a partition mounted as "/home." We'll see how this works over the long run.
To do the partitioning, I used "gparted" command, which conveniently, was already installed on the memory stick version of linux. How cool was that? I chose the "swap" partition type for the swap space, and ext4 for the other two. Windows can't read ext4 partitions natively, but I'm hoping that the partition will be readable by Windows programs running in Wine or VirtualBox (see my prior post).
After running though the installation, I rebooted using my external drive. Pretty slick. I'm a linux user.