Mindfulness in Plain English by Bhante Gunaratana. A great introduction to meditation practice by a very experienced Sri Lankan monk practitioner and scholar. The title says it all.
Eight Mindful Steps to Happiness by Bhante Gunaratana. An excellent summary of the eightfold path.
Loving Kindness: The Revolutionary Art of Happiness by Sharon Salzberg. Great introduction to metta practice and other heart practices of meditation, with great teaching stories by one of the founders of Insight Meditation Society.
Who Is My Self? by Ayya Khema. A clear introduction to concentration practice (jhanas) in a down to earth way. Written by a German Buddhist nun who spent a lot of time practicing in Sri Lanka.
In The Words of the Buddha translated by Bhikkhu Bodhi. An introduction to the direct teachings and stories of the Buddha (the suttas) through the translation of an eminent American scholar/monk. If you like this you can move on to reading the sources from which this book is excerpted.
The Noble Eightfold Path by Bhikkhu Bodhi. A succinct introduction to the main teachings of the Buddha, including mindfulness Can be found online as well.
A list of online Insight Meditation groups
Weekly Meditation groups in the Bay Area led by Spirit Rock Teachers
Spirit Rock Meditation Center Marin County, CA
Insight Meditation Society, Barre, MA
East Bay Meditation Center, Oakland, CA
Insight Meditation Center, Redwood City, CA
Aranya Bodhi Hermitage & Dhammadharini Vihara (Women’s Monastic Community in No. CA)
Aloka Vihara women’s monastic community in No CA
Cambridge Insight Meditation Center, Cambridge, MA
List of meditation groups around the US from Buddhist Insight Network