Ubuntu is an awesome LiveCD and so **** easy. I just tried it a few days ago and it was so **** simple. Then after I got a good feel for it, I installed it over an old Win ME machine and it practically installed itself! I recommend Ubuntu.
I don't entirely understand your question. Are you asking how to use a LiveCD? All you have to do is make sure your boot sequence is set where your CD drive will boot before anything else.