Some cool books:

Tantric Quest by Daniel Odier. This book is a quick and easy read and tells Odier's true story of his initiation by a classical tantric dakini in India.

Jewel in the Lotus by Bodhi Avinasha and Sunyata Saraswati. A good basic book on tantric techniques.

Tao Te Ching, translated by Gia-Fu Feng and Jane English. The Tao Te Ching is nearly mandatory!

The Encyclopedia of Sacred Sexuality by Rufus C. Camphausen. This book knows everything!

Organizations:

Ipsalu Tantra This is where I first learned about tantra. Ipsalu blends classical tantra with modern psychological techniques, and is spiritual and just juicy enough to make it interesting for most Americans.

Portland Tantric Meetup I'm biased, but this is a great community of tantric practitioners devoted to living a tantric, spiritual and fun path.

Sacred Tantra Club A great resource for tantra events, especially pujas, in the Portland area.

JayaKula.org Shambhavi Saraswati teaches true Kashmir Shaivite tantra here in Portland, and is a tremendous teacher and resource.