Getting started with mindfulness
Mindful.org is an excellent resource for down-to-earth articles and guided practices.
This page is one of my favorites for getting acquainted with mindfulness practice. It includes audio guides for a 5-minute breath meditation and a 3-minute body scan at the bottom of the page. These are the practices I recommend to beginners.
Video: "You are not your thoughts"
Jon Kabat Zinn, a pioneer of research on Mindfulness-Based Stress Reduction, talks here about the brain science underlying mindfulness.