If you are new to mindfulness and meditation (and even if you are not!) Rehena has kindly put together a list of recommended books, websites and courses/retreats here.
There are many other wonderful resources that you may find useful:
Talks by Thich Nhat Hanh and monastic Dharma Teachers
Details and links to videos and audios of talks by Thich Nhat Hanh are available from tnhaudio
Another wonderful source of videos of talks is Plum Village Online Monastery which has recent talks from Plum Village and Blue Cliff Monastery (in English, French and Vietnamese
Talks by Insight Meditation tradition Dharma Teachers
Details and links to podcasts of talks by Gaia House and other teachers are available from http://www.dharmaseed.org/talks/ There is an RSS feed you can sign up to for individual teachers.
Talks by Ajahn Brahm
Another wonderful resource of Dharma talks that are both profound and often very funny is the feed for recent talks by Ajahn Brahm.