OSDisc.com

One of the best places on the internet for getting Linux distributions is OSDisc.com.  This website has different types of Linux operating systems on CDs and USB drives.  I highly recommend the Ubuntu and Linux Mint CDs.  Both of these operating systems are user friendly.  I have used the Ubuntu system solely in the past on one of my computers, and I currently have a dual-boot setup with Windows and Linux Mint on my main computer.  It is great to have a Windows alternative if you need it or want it.