There is one thing to be warned of when using a live CD. Most will allow you to log in as 'root'. When talking about Linux, if you substitute 'root' with 'god' in your mind (notice the small G, I'm not out to start a religious war here) you will have an understanding of the power of 'root'. Root can do anything it is possible to do, including formatting hard drives, destroying data etc. The rule is simple:
NEVER LOG IN AS ROOT, ALWAYS USE THE GUEST ACCOUNT on a live CD, unless of course you are planning to install it on your system at the time you log in.
While root allows you to do pretty much anything, other user accounts (guest for example) protect you from doing anything potentially disasterous.
There are many many different Live CDs now and the best way to find them is to go to one of the many linux sites or simply use Google to search for 'linux live CD'. When you have found one you want to try, download the ISO image and use some CD burning software (something like Nero) to burn the image to a CD.
How do you actually use a Live CD? Simple. Ensure your computer can boot from it's CD drive (you may need to change the 'boot order' in your BIOS settings) and then pop the Live CD into the drive. Then start the computer. Your Live CD should load without problems on all but the very oldest computers or the very newest computers. This part can take a few minutes. Loading from CD is *much slower* than loading from a hard drive.
Live CD things to remember:
- The more RAM in the computer the better. Most Live CDs require a minimum of 64Mb.
- An OS loaded from a Live CD will run slower than it would if it was installed on the HD.
- If you have enough RAM (768Mb+) some Live CDs will allow you to load them directly into memory meaning the OS will run faster (though still not as fast as a propper install).
- Do not log in as root unless you are confident of what you are doing.
And finally... have fun!