MyDirectives makes it easy to create a personal emergency medical directive including information critical to healthcare providers as well as personal thoughts with as much detail as you wish. MyDirectives can also be linked to the iPhone Health App which is accessible even when the phone is "locked". A critical feature in an emergency situation when one may be incapacitated.

Compassion & Choices is the nation’s oldest, largest and most active nonprofit organization committed to improving care and expanding options for the end of life. They provide information and tools, including a free consultation program, to help individuals receive healthcare that is consistent with their values and priorities as they approach the end of life.

Talking about end of life care is often difficult, especially with loved ones. The Conversation Project is a wonderful organization dedicated to helping people talk about their wishes for end-of-life care. Their website provides a "Starter Kit" to help individuals have "the conversation". 

CaringInfo is the successor to the National Hospice and Palliative Care Organization. Their website has useful resources and guides to help you make informed decisions about care and services and for understanding topics like advance directives, palliative care, caregiving and hospice care.