In the listing of the 100 most frequently challenged books from 1990–1999, according the American Library Association, this ultimate how-to book is 29th:
Final Exit: The Practicalities of Self-Deliverance And Assisted Suicide for the Dying – By Derek Humphry
Now in its 22nd year of publication, it still sells daily around the world. Third edition, 2010, paperback or ebook at www.finalexit.org/ergo-store