Mindfulness by John Kabat-Zinn is a great way of relaxing. It's a Buddhist form of meditation where you focus only on your breathing and nothing else. Youblock out all sounds, objects and thoughts and concentrate on breathing alone.
It's pretty difficult to begin with, it's really hard for your mind not to wander and it takes practice, but you will feel great afterwards.
Either look him up on youtube or try buying one of his CD's. I got given a few of them by my old teacher in High School but I guess you could try ebay or amazon or somehing to get one