Looking back, Virualbox has been the most important discovery of my Linux journey because with it I can freely create a virtual machine to test any Linux distribution.
Virtualbox also allows me to reset the virtual machine back to any of its previous saving points (“snapshot”), that means I always have other chances if I screw up something.
Given all that, I recommend you to try this guide on a virtual machine prior to on your real system.
Here is my video that show you how to install a Virtualbox:
It is recorded in HD, please select HD resolution for the best experience.