Because some people think this is a good idea. . .

I'm here to help you get started with Linux. I first installed in 2002 and have been a Linux sysadmin and a distro maintainer professionally. This is going to feel like a very in-depth guide for some of you and for others this will be a barely adequate overview.

Why try Linux?
Honestly, I don't care what your reasons are, and I don't care if you try it or not. It's really not for everyone, no matter what Canonical tells you. Linux is a lot of things to a lot of people, but generally it is a more enjoyable experience if you like tinkering and figuring things out. It's primary use is for business and hobbyists and if tinkering with your computer sounds like a fun hobby, then this will probably be an enjoyable experience for you. If all you want is an OS that won't break then you certainly can get that with Linux, but I would expect it won't feel like its stable or any better than what you currently have until you've spent about 1-2 months learning the ins and outs. Personally, I think it's worth that time investment because what I learned has last me my whole life and been a boon professionally and personally.

Whatever your reason, always remember the Linux warranty: if you break it, you get to keep both halves.

So, onto the "how" to get started with Linux. Essential tools:

Spare computer - I recommend having at least one other internet-capable device to assist you in learning and lookups while getting things setup or in situations where you've broken your ability to connect.

Install media - Get a USB thumb drive that's at least 8GB in size and download Balena Etcher (https://etcher.balena.io/) This will let you convert an installer image into a bootable usb drive.

Install image/file - this is a file downloaded from the internet, typically a .iso or .img file. You can get this from the Linux distro's website.

What's a distro?

It's a distribution of software. What's that mean? Well, it's a group of IT nerds who said, "I want my computer to work like. . .this" and then shared the results with others. Some are backed by companies, others are passion projects. This group then tries to make all open-source software available and working in accordance to their preferences. Most software installed on your Linux computer will go through the distro maintainer's loving hands before it reaches you so they can verify it actually works as intended.

Not all distros are equal, or even trying to be. They are made with a specific goal in mind and every bit of software they make available will be adjusted to suite their tastes. Feel free to checkout DistroWatch.com for their analysis of each distro and they rank them based on downloads. Shop around, find one you like, and then grab the install iso from the distro's website.

You want my preference? No, I won't go there. I make my own distro and it is solely for me and you can't have it and I won't be pulled into another flamewar.

Now to the meat of this. There are thousands of guides out there and if your search-engine-fu is good then find one specific to your exact distro with it's accompanying release version.

In every case, you will need to tell your computer to boot to your install media. This has to be done within the first few seconds after you press the power button and turn it on. Smash every F# button at the top of your keyboard, along with Esc, Enter, Delete, and Insert over and over until your computer does something unexpected. (you can lookup the exact key by your computer's make/model) This will interrupt your normal startup and tell your computer you want to do something different.

If you're successful, you'll either get a list of bootable devices, or a screen that lets you configure the low-level settings on your computer (it's called the UEFI utility and colloquially called the BIOS in tech circles). If you get in the former, find your USB key you made with Etcher and you'll be off to the races. If it's the later, then go to the menu that indicates you want to quit and there will usually be an option to select which bootable device you want to use. Every computer manufacturer does this a bit different so it's best to just get familiar with it for your computer since you're about to become much closer friends and it's best to get secrets out of the way early in the relationship.

If it finds and boots to your USB install media, then you'll see the bootloader screen for Linux (called GRUB, or the GRand Unified Bootloader).

It looks something like this:

You can customize this later if you're so inclined. I made mine say "Tygglinux" and when I built one for a friend I themed it heavily with Hannah Montana because, well, what other choice is there for a windows sysadmin looking to get a learning environment for Linux?

The Live option means that you're going to run the distro JUST OFF THE USB DRIVE. This means as soon as you shutdown, there's a high chance that everything you did will be lost and it'll go back to its original state. Think of it as a "try before you buy" option if you want to do some more in-depth research while shopping for distros.

Most of you will want the installer. It'll ask you some basic questions about timezone, what kind of keyboard you're using and what you want to name this computer. Everything will seem pretty straightforward until you get to the part about setting up your hard drive.

This is going to be your first technical bit in Linux. This part is called partitioning and it's just like partitioning a room--you designate space on your hard drive for a specific use. "Guided" will be the easier group of options to choose and many installers will explain the consequences of your choices as you make them.

This part is inherently risky. Removing the partitions on your hard drive makes it so your computer can no longer distinguish what that space was used for. In more basic terms, removing all the partitions will also REMOVE ALL THE DATA ON THE HARD DRIVE. All your pictures, all your backgrounds, all your programs, absolutely everything. Deleting a partition deletes all the data on it (from a practical perspective) so be aware that if you tell it to "use the entire disk" then there is no going back once the install starts.

It's possible to setup a dual-boot environment if you don't want to just jump in the deep-end and a lot of the beginner-friendly distros will make that process easy. . .ish.

Linux desktops only technically need two partitions, and one probably already exists: The EFI partition and the root partition (often shown as a single forward-slash / ).
You can add more if you have reason to. Remember the Linux warranty? Well, if you happen to fill up your hard drive, Linux will let you, and stuff will break pretty quick when it does (like graphical logins). Setting up partitions to ensure that your game installs or movie libraries don't interfere with the space needed to run your OS is often a good idea. In my case, I put two physical hard drives in a redundant setup that forces data to be written to both simultaneously for my OS, and put all my Steam games on a different hard drive that lives at /mnt/steam.

Here's a good visualization of a hard drive. Your installer might show this a bit different, but the concepts will be the same and there will be something similar for every installer.

The bar at the top shows how the space is currently divided and the color differences in the box shows how much is being used.

In the table at the bottom, this shows how the computer sees the partitions. You can see the two essential partitions here.

Anything that starts with /dev means a physical device, and in this case a block storage device (which is a more generic term for a hard drive). sda in this picture is a 10GB hard drive (and you can see it indicate that in the top right drop down). sda1 means the first partition on the sda drive.
You might also see /dev/nvme0n1 which means you have a nvme hard drive (they tend to be the fastest). xdva is another convention used to name hard drives and /dev/md is a group of hard drives that want to appear as one.

Look closely at the third line in this table. The key icon indicates that it's encrypted, the color box is just a key for reading the bar graph above. File System indicates how data is organized within the partition. ext4 (short for extension version 4, but I've most commonly heard it spoken as X-T-4) is the standard/default for most Linux file stores. You might see NTFS, which is New Technology File System and indicates where Windows is using your hard drive, and fat32 is the File Allocation Table system that we commonly use on USB thumb drives and other OS-agnostic or low-level system media. If it says "extended" anywhere, that's just a bucket for more partitions. It use to be important for partitions beyond a certain size, but now it's just kinda legacy tech leftover from the 90s.

There are a lot of options for Linux partitions and I don't want to overwhelm you. Each one was designed for a slightly different use and it is worth it, eventually, to figure out which one is right for your setup. I use ext4 for my root partition because it's proven to be a good balance of flexibility and resiliency, but I use xfs for my steam games because it improves load times and I don't care if I have to reinstall those in the event of a crash.

Next on the line is the Mount Point. This indicates the location (and to some extent the purpose) of this partition to your Linux OS. The two needed partitions are at /boot/EFI (which probably already exists) and / (pronounced root). I'll make a follow up post that goes through basic usage and concepts for Linux if this is popular enough to motivate me to do more.

Size, Used, Unused are pretty self-explanatory--how big is your drive and how much are you using.

Flags indicate a simple purpose for the partition. In this case, one is marked as the partition we should try booting the computer from.

If you've made it this far, then you're almost done with the install. There's really only one more bit to cover: how you install software in Linux.

When you install "Linux" you're actually installing upwards of 1200 unique software packages. In the picture above, your initial install will grab this software from the install media you made.

In daily operation though, your Linux OS will connect to a server provided by your distro called a repo (short for repository). This will contain tens of thousands of programs that are freely available and have (probably) been tested and verified to work on your OS.

For Windows users, you tend to install software by doing an internet search for a program, downloading a .exe and running it.
Linux is nothing like that. You find out which package manager you're using, and just pass the name of the program you want and it does the rest. If it can't find it, then you do an internet search for the repo that contains that software and add it to your package manager. I have good success finding software by just typing "Linux video editor" or "FOSS equivalent of photoshop" and that'll get me the name to pass to my package manager.

In the picture above, the installer is giving you the choice to install directly from the repo by changing the Installation Source and it has some pre-defined groupings of software suited for a specific task. You'll usually see things like "file server" or "web server" or "workstation" listed here.

When all is said and done you should end up with your shiny new Linux OS, which looks something like this:

You were probably thinking it was something more like this:

And it certainly IS Linux, but it's more accurate to say this is Linux software, called Gnome. Even the picture of a terminal above is (much simpler) software, but it's good to think of Linux in both terms (see what I did there? terms, terminals. . .)

And that's pretty much it. It'll ask you to reboot and then you'll see GRUB each time you turn your computer on. The choices it presents will default to a normal Linux boot, and you'll usually see a recovery boot option in there somewhere and some of the fancier distro maintainers will include entries for your EFI Utilities/BIOS.

Load it up and press your "Windows" key and start typing to see what software is available to you. We actually call it the meta key and we bind the mac cmd key to it too. You might find a graphical software installer by typing "software" and that'll give you a small set of what's available in the distro's repo.

I recommend typing "term" and getting a terminal open like the one above because Linux developers won't often put in all the effort it takes to make a GUI to do software installs. Consequently, the command-line in Linux is infinitely more powerful and capable than the desktop graphical interface, but it requires that you do some reading and learn-up on how stuff works to really utilize it.

Find out which package manager your distro uses (apt or dnf are most likely), and then type "man apt" or "man dnf" to read-up on how to use it. That should get you started and give you a fighting chance to make Linux work the way you want it. Remember that "man" command (short for manual) because it can teach you most everything you need to know about Linux. In fact, those man pages are so helpful that asking questions to the Linux community at large will often yield a for letter response:
RTFM - Read the freakin manual
Also heard it as "Read the fine manual" but it seems any f-word will do