Ms. Newberry’s guide fills a gap; I know of no other precise instructions for preparing, publishing, and preserving an obituary. Her book is written with a measure of sensitivity and focuses on making a difficult emotional process more manageable for the grieving. She provides a good collection of poems and Bible verses, a series of obituary templates varying by length and style, and links to online memorial sites. 
The guide is successful at concisely providing information and ideas; the contents fulfill the promises of the title and cover. Instructions for preserving the newspaper clipping are a nice touch.
The book could be improved by the addition of recommendations for those writing obituaries in advance of death, who may have more time and more energy to invest in the process. A few basic tips and reminders about good writing and editing would not be misplaced. (Obituary typos and blunders can be amusing to strangers, but are very unfortunate for the family and friends that wish to treasure and preserve the obituary.)
I believe a satisfactory, even strong, obituary could be produced using this guide alone. Even the best writers will want feedback and editing before publishing such an important work.
The guide is available electronically or in print from amazon.com, barnesandnoble.com, or via howtowriteanobituary.com