This guide will show you how to easily upgrade your current Mac OS X for free to the latest version: El Capitan
Before you think about upgrading, be sure that your Mac is recent enough to be able to upgrade.
To find out what version of OS X you are running click the Apple icon in the very top left corner, and then click "About this Mac".
You must be running one of the following MacBooks, Mac minis, Mac Pros or iMacs as listed below:
Upgrading to El Capitan is very safe and hardly anyone has any issues, but it is always a good idea to backup your Mac first.
We recommend that use use Apple's built in "Time Machine" features to fully backup your machine.
It is a very easy process, and the only thing you need is an external hard drive. You can find some cheap ones at Amazon.
We recommend following the official guide here.
There are some other (cloud based) backup options, not from Apple. We would recommend Backblaze over the other three, but they are all good options from trustworthy companies.
The actual upgrading is very simple, and is done simply through the Apple Mac App Store.
Upgrading to El Capitan is done through the main OS X App Store application.
Click the Apple icon in the top left corner, then click "App Store...".
Once the App Store application is open you should see a big banner for upgrading to El Capitan!
It costs nothing to upgrade, and has lots of new features.