Suicide and Attempted Suicide by Geo Stone is generally acknowledged to be the most comprehensive work on methods of suicide, although the book is not currently in print, and obtaining a copy is expensive.
The Peaceful Pill Handbook is available as an ebook and is updated regularly. It focuses on methods of ending life using drugs, and has a lot of information about where to source (generally from overseas) one of the most effective drugs for peaceful death, Nembutal. It also explains at length a method for suicide involving an exit bag and helium.
The Final Exit by Derek Humphry was updated in 2009 and is also acknowledged as a very useful book on this area.
More information about these books below:
The Peaceful Pill Handbook, Philip Nitschke & Fiona Stewart (USD $35/$85 for online edition)
This really is the premier publication for anyone wanting more information about painless end of life choices. Thoroughly researched and regularly updated (if online edition purchased – the cost includes two years’ of updates), this is the most comprehensive publication for information on using drugs and gas as a suicide method. It is aimed at people over the age of 50 who are considering their end of life choices due to the onset of terminal illness or declining health. See www.peacefulpillhandbook.com.
Five Last Acts - The Exit Path: The arts and science of rational suicide in the face of unbearable, unrelievable suffering, Chris Docker (from around USD $45)
The Exit Path provides detailed information on the use of helium in self-deliverance, the variations and how to eliminate failures. The book examines differences in the action of sleeping drugs, what to use, and how. It reveals metadata on the properties of anti-emetics to help select the best solutions. The Exit Path analyses differences between fasting in hospital and fasting at home, and provides handy checklists so readers can stay on top of the many dilemmas that arise as life approaches its end.
Geo Stone, Suicide and Attempted Suicide (from around USD $110)
This is essentially a guide on how to commit suicide, or alternatively, stage a "safe" suicidal gesture. Stone (who studied pharmacology at George Washington University Medical School and the National Institutes of Health) sets out his basic premises: first, that it is each person's right to make decisions concerning their own death, and second, that most decisions to commit suicide are due to temporary problems and are therefore tragic mistakes. Stone goes on, in a pragmatic tone, to set out an immense amount of information on suicide and attempted suicide.
Final Exit, Derek Humphry (USD $17 or $21 for the ebook)
A compassionate and sensitive guide designed for terminally ill people who wish to end their lives. It covers all the practicalities involved in self-deliverance. From the importance of certain documents, to the law, to consideration of others, to the pros and cons of various methods (including certain drugs). It contains clear instructions for supportive doctors and families so they can keep a person's dying intimate, private, and dignified. See www.finalexit.org.
The Good Euthanasia Guide, Derek Humphry (USD $16)
Reference book for those who wish to know more about commonsense choices in dying at the end of life. Contains an annotated list of every right-to-die group in the world and descriptions of the assisted suicide laws in almost every country. Describes in detail how aid-in-dying laws are functioning in the Netherlands, Belgium and Oregon, and has details about the work done by Dignitas and EXIT in Switzerland. See www.finalexit.org.