Here are some websites with general information and resources on advance directives. 

American Association of Retired Persons
Provides information on advance directives and includes information on where the AARP stands on end-of-life issues. Links to other sites are also provided.
http://www.aarp.org/endoflife/

Advance Care Planning: A Practical Guide for Physicians
This publication, available for purchase from the AMA Press,  helps health care providers structure and facilitate conversations on advance care planning.
https://catalog.ama-assn.org/Catalog/product/
product_detail.jsp?productId=OP318800%20

Hospice Federation of Massachusetts
Information on hospice care, decision-making tools, and a hospice locator.
http://www.hospicefed.org

National Hospice and Palliative Care Organization
Information on advance directives, health care agents, and other end-of-life care issues.
http://www.caringinfo.org

Growth House, Inc.
A gateway to resources for life-threatening illness and end-of-life care.
http://www.growthhouse.org

On Our Own Terms: Moyers on Dying
Provides end-of-life tools, resources, and care options. Learn about solutions for finding a better death and explore the options for humane care for the dying.