Pam discussing meditation
The Chopra Center
The Chopra Center iTunes library of 24 free guided meditation podcasts.
Beliefnet
Beliefnet features both guided Christian meditation, as well as guided Buddhist meditation.
Along with these, there is also a very informative section on styles of meditation from around the world.
UCLA - Free Guided Meditations
Free guided meditations from the UCLA Mindful Awareness Research Center.
About Meditation
The 9 types of meditation explained.