For those who require a step-by-step guide, here's a walkthrough for how to install my personal favorite desktop GNU/Linux distribution, Arch Linux.

If you'd like to follow along in text form, here are the relevant pages on the Arch Wiki:
- General installation guide: https://wiki.archlinux.org/index.php/Installation_guide
- Partitioning: https://wiki.archlinux.org/index.php/Partitioning
- Bootloader installation: https://wiki.archlinux.org/index.php/Arch_boot_process#Boot_loader
- General post-installation guide: https://wiki.archlinux.org/index.php/General_recommendations
- Adding a user: https://wiki.archlinux.org/index.php/Users_and_groups#User_management
- Setting up sudo: https://wiki.archlinux.org/index.php/Sudo#Configuration
- Installing a display manager: https://wiki.archlinux.org/index.php/Display_manager
- Installing the SDDM display manager: https://wiki.archlinux.org/index.php/SDDM
- Installing a desktop environment: https://wiki.archlinux.org/index.php/Desktop_environment
- Installing KDE Plasma (and KDE Applications): https://wiki.archlinux.org/index.php/KDE
- Prevent a black screen when booting in Intel mode on an Intel/NVIDIA switchable-graphics machine: https://wiki.archlinux.org/index.php/NVIDIA_Optimus#Display_managers