Let's go for it! So you have decided to use an operating system which is both free in cost and also has its source code open? Well done. Let's now get down to work. I'm of the opinion it is better if you test Linux operating system (operating system = OS) first, WITHOUT changing anything on your pc.
This allows you to have some practice with it before any changes take place on your pc! Most linux distros, which is both an OS plus a selection of programmes, will give you the opportunity of trying out your new OS without changing any settings in your pc. So actually you will not be running into any trouble.
Let me explain: as Linux is open source, unlike MS Windows which has closed proprietor source code, there isn't just one distro, there are so many to choose from. If you want to have a look, just go to the distrowatch website.
I am personally in favour of the Linux Mint 17.1 distro (called Rebecca). You can use this version for the next 5 years and it is fully supported with updates. After this period there will be a new Linux Mint version issued (But don't worry...it will still be 100% compatible with this one).
Here comes the guide (other people have already asked for such help!) on how to burn a DVD to use it as a LIVE DVD e.g. using the live disk OS without changing anything from your pc!
Guide 1 This is a step by step guide. It's useful because it tells people what to do if they are using Windows 8. Please read carefully about the BIOS setup as otherwise your PC might never boot (starts again) on linux!! In the BIOS you have to make sure that your PC boots up on the DVD first and not on the harddisk.
Guide 2 This is a video about Ubuntu live DVD (it's another Linux distro, which is very popular).