Installing Debian

Debian GNU/Linux is one of the oldest, most stable and trusted distributions out there. As a result many other distributions, such as Ubuntu, has been based off of it.

The pro of Debian is that each package is rigorously tested before release so stability is basically a guarantee, the problem is of course that you will almost indefinitely end up with out of date versions of all your programs.
Of course if you prefer more up to date software above guaranteed stability there is always the testing-branch of Debian, but I do believe most users tend to install the Stable version.

I must admit I'm slightly biased towards Debian because back in 2000 when I took my first OS course this was the distro we used.
I quickly forgot nearly everything I learned, but I do distinctly remember our teacher forbidding us to install a desktop environment with the motivation: "That would be like clicking Windows, and that's not a real operating system".

Interestingly each Stable version of Debian is named after a character from the Toy Story franchise.
For instance the latest version (as of writing this article); version 9 is named Stretch.
The previous, version 8, was called Jessie.

Jessie and Stretch in Toy Story 3

Installing Debian is really rather easy, but it does pertain some more steps than Windows or the Linux distros that are made explicitly to be easy for beginners.

Furthermore, if you want to be able to dualboot with Windows (being able to choose to use either Windows or Debian on the same machine) you will first have to prepare your hard drive for that.

How to prepare for dual boot with Windows

While installing Windows

In case you want to be able to dual boot with Windows, you really need to install Windows First, because Windows will ignore any other OS installed on the system, and just write over the MBR, whereas Debian will recognize another OS and automatically make you able to choose which OS you want to boot in to.

In this case you should really make sure you leave some free, unpatrtitioned space on the hard drive while installing Windows, so you will have somewhere to install Linux later.

While making a partition for windows, you should save some space for Linux
(the extra 500MB partition is created automatically by the windows installer)

Resizing partition from inside Windows

If you didn't, and have your entire drive partition for Windows, you actually can resize the partition while logged into Windows, but this might be somewhat risky, and you should really back up any sensitive data just in case.

If you need to resize in Windows, first right-click the start-button, then select "Disk Management". Now choose the partition you want to resize and select "Shrink Volume". Now enter a size that will leave enough empty, unpartitioned space on the disk to make room for your Linux installation and anything you want to add to it.

Installing Debian

First off go to https://www.debian.org and download the latest iso.
If you instead want to buy a physical copy, there are some retailers who sell cds, dvds, and even usbs of Debian (check the homepage for a list).
There are also some books about Debian that comes with install discs. They are of course likely to not contain the latest version.

Burn it to a CD, or write it to a usb stick, or however you prefer to install.
You can use tools such as UNetbootin or YUMI to easily create bootable usb sticks from iso files.

Make sure that your computer boots from the usb or cd or whatever medium you use to install from.
This might mean you will have to change boot options in your bios (usually by pressing Del during boot up) or that you have to enter boot options during startup (Usually by pressing F8 or F12 during boot).

Once you have started your computer with your install medium you will be presented with this screen:

Choose either Install or Graphical Install. They are essentially the same, only the Graphical Install looks more modern and uses the mouse.

Choose Language (Install)

Choose Language (Graphical Install)

First choose a language for the installation, and your location.

Configure locales

Choose Location

Then choose your locales (i.e. what language will be used by the installed system).

Choose your keyboard layout.
Then choose a hostname for your system, it can be anything you want. This is the name of your system as seen by other computers in your network.

Hostname

Keyboard

Then choose a domain name. If your are installing on your home network or your home computer, this can be anything you want. The best choice in this case is probably to just keep it empty.

Root password

Domain name

Next choose your root password (the root user is the administrator of the system). Obviously you should use a Good password here, not the worst password ever as in the example screenshot I took.

Users full name

Users username

Now enter your primary users full name (you Must have at least one user other than the administrator).
Next enter the users username. The default suggestion will be the users first name in all lower case, but you can change it to whatever you want.

Main users password

Choose timezone

Now choose the main users password (again choose a good one).
Next configure the clock by choosing your timezone.

Partition disk(s)

Then it's time to prepare your hard drive for the system.
If you're going to use Debian as your only OS just use the first option "Guided - use entire disk".
If you want to have multiple Operating Systems, be careful not to overwrite any partition with a system already installed to.
If you plan to install an additional OS later, choose manual so that you can make sure enough space is left on the drive to accommodate that system.

If you have Windows already installed choose "Guided - use the largest continuous free space" and the installer will automatically use all the free space to create the needed partitions.

Guided partitioning options

Partitioning summary

You can then choose if you want to make separate partitions for some folders.

It is easier to use only one partition for the entire system, but putting the /home folder on a different partition can be a good idea if you want to be able to just cleanly reinstall the system, or even install a completely new distro, but keep all your personal files and configurations.

Even if you choose to use the entire partition, it will still create a swap partition.

If you choose to manually create the partitions, remember that you must at a minimum have one swap partition, and one root partition that must be mounted as /.

After choosing to continue you will get an overview of the partitioning and asked if you really want to write the changes.
Caution: if you change or use existing partitions any data on them will be removed.

Installing base system

Using further installation discs

After the partitioning has been written the system will start installing to the root partition.

Next you can choose whether you have further cd/dvds with supplemental software. This step is really just necessary if you don't have a network connection, since you can otherwise install any additional software from the net.

Choose location of your mirror

Choose a mirror

Next it's time to configure the package manager.
This entails choosing a mirror to download all your packages (software) from.
Choosing one that is close to your physical location is most likely to make the downloads go faster.

Proxy information

If you need to use a proxy, now is the time to enter your proxy information.
If you have no idea what this is you most likely don't use a proxy, in that case you should just leave the field blank and no proxy will be used.

Package popularity

Next you are asked if you want the system to anonymously collect information of what packages you have installed.
If you are paranoid choose No.

Software selection

Next you can install additional software. In case you intend to use it as a server you probably don't need a desktop environment. Otherwise choose one (or more) that you like. Both Gnome and KDE are really large full-fledged desktop environments, where the default configuration of KDE reminds a bit more of Windows. Xfce is a more light-weight environment.
You can of course install even more desktop environments and window managers after the system is installed.

Other Operating Systems

Choose disk for boot loader

While installing the boot loader, the computer is scanned for other Operating Systems. If found you get the option to be able to choose between them at start up.
Choose which disk the boot loader should be installed to...

Installation finished

And you're done!
Congratulations on your new Operating System!

GRUB Boot Loader

If you chose to dual boot with another OS, at boot time you get to select which one to start.

Graphical Login into XFCE

If you installed a desktop environment you get a graphical login screen, otherwise just text. Type your username and password to log in.

Supplementary

If you messed up and installed Windows After Linux, the boot loader will be overwritten and you won't get a choice to boot anything but Windows.

This can be fixed with the Debian Installer by doing the following:

After booting up the installer choose "Go Back" at an appropriate time, and you will get a listing of all the installation steps.
Instead of going back, go forward to the section Install Boot Loader.
At this point the installation will scan your system for other operating systems and write the boot loader to disk.
After that just reboot your computer and you should be presented with GRUB that offers a choice between your operating systems.