Another source of free guided mindfulness meditations emerges: Spotify. Here are a few collections that showed up in a search there. Plenty more where these came from. Enjoy.
Judith Day – Introduction To Mindfulness Meditation
Jon Kabat-Zinn – Mindfulness Meditation For Pain Relief
Elisha Goldstein Ph.D. – Mindful Solutions For Stress, Anxiety, And Depression
Jack Kornfield – Guided Meditations For Difficult Times