Linux is free, which means you can try it out for yourself on an old PC (or a new one if you are brave enough) and not have to worry about breaking the bank.
To try Ubuntu simply go to http://www.ubuntu.com/download/desktop and download the software. It is fairly large, so you will need a DVD (not a CD) or USB stick to create a bootable disk. There are instructions on the site that explain how you can create a bootable disk. The easiest is probably the DVD method, as that usually means right clicking on the file (it ends with .iso) and selecting to burn it to DVD.
Once created, you will need to tell your chosen computer to boot from the correct drive (DVD or USB) and then follow the on screen instructions. Usually pressing F8 or one of the other function keys while booting up allows you to choose a different drive.
Did you know that Google’s ChromeOS which sits on Chromebooks is based on Linux? There is a handy website that has a version of ChromeOS (called CloudReady) that you can use to turn any PC into a Chromebook. The address is www.neverware.com. The initial download is less than 1 GB zipped, but expands to 5.5 GBs when unzipped. You will need to use a USB to create a bootable disk. The easiest way to do that (following the instructions given) is to use the Chrome Recovery extension in the Google Chrome browser. Set up is simple and straightforward after that. By default the CloudRead will run straight from the USB stick, which doesn’t do anything to your hard drive. It is only while logged out that you will find the option “Install CloudReady” in the system tray. Ubuntu also has an option to try before installing.
Bear in mind that when installing a new operating system, it will replace the existing contents of the hard drive on that machine. Ubuntu does have other options so you can dual boot with another operating system, but if you’re testing it out on an old machine that doesn’t really matter.