About KDE neon
KDE neon is a set of repositories via which KDE is distributed. It is also a set of disk images which contain easily installable versions of Ubuntu with a minimal set of apps and a KDE Plasma desktop, as well as a preconfigured KDE neon repository of your choice.
Neon's website is neon.kde.org. Go to "Download KDE neon." You will see four available images: User, Developer Testing, Developer Unstable, and Developer. Docker images are not recommended for new users.
The Developer Unstable Edition is for those who can endure noticeable bugs and literally cannot wait for new features. The Developer Testing Edition provides only bugfixes to the latest official version of KDE. Attempts to fix bugs can cause more, though. The normal Developer Edition is for KDE developer, with the development libraries already installed.
The User Edition is recommended for everyday users, and also for those who are overwhelmed by that last paragraph.
Once you have the image, you have two options: write it to USB with KDE/ROSA Image Writer, or burn the image to a DVD. For burning the image to a DVD, use your favorite DVD burner. If you don't have an optical drive or find it too slow, download ROSA image writer and write it to a USB flash drive. Then reboot your system.
You should be greeted with the Plasma desktop of KDE neon after a couple of loading screens. Click "Install neon User" and wait for the installer to appear. Follow the steps of the installer until Disk Setup. At this point, you are given a choice. Use the entire disk, or install alongside existing OSes? More advanced disk setup can use existing home folders and overwrite OSes; future versions of neon will make overwriting OSes easier.
If you haven't backed up your Windows files and/or you are unsure if all of your needed applications have equivalents for Linux-based systems, install alongside Windows. Otherwise, use the whole disk. This will begin the installation. Quickly but carefully, select your timezone and set user data. Then wait for the installer.
If you want, play around with KDE until you see the message that installation has finished. At that time, restart your computer by clicking the icon in the bottom left corner, then going to "Leave" and clicking "Reboot." If all goes well, you should see a menu with the options: "neon GNU/Linux," "Advanced options for neon GNU/Linux" and "System Setup." If you installed alongside Windows, you should see an option for it as well.
After installing, browse the software manager, Discover, and find any applications you need. Most likely these include an office suite, a finance manager, and an email client. We recommend installing either LibreOffice (unofficial, but works very well with KDE) or Calligra (developed by KDE) as an office suite. For an email client, there's KMail and Thunderbird. For a finance manager, KDE creates Skrooge and KMyMoney, but GNUCash is also available.