The Tibetan Book of Living and Dying by Andrew Harvey, Patrick Gaffney, Sogyal Rinpoche, Sogyal (1992, Hardcover, Illustrated)

This is one of my favorite books. When one of my friends was dying, I referred to it and it helped me getting through the hard time. It talks about how in our western culture death is such a taboo, as well as aging being seen as something negative. We are faced with our own fear of death when we are talking to a person who is dying. The book offers an insight into how Buddhism inticrates death as a part of life as much as birth, what happens when people are facing death and how you can help by being with the dying person. There are also excellent meditation instructions. Excerpts of the book can be found on this website:
http://www.rigpaus.org/WIR/TBLD/Understanding_death.html