You'll have to consider what to list as reputable credits. For instance, it wouldn't be a good idea to list school or college assignments, unless you have a thesis relevant to your submission. Non-paying markets might also be a no-go. Newspaper articles, stories, and reviews might be okay, if the paper in question is a large daily or weekly edition. List any journalism experience, as a reporter or column writer. The key here, is to list paid publications from semi-pro or professional sources. If you want to list non-paying small press articles and stories, you can do this, but it won't make an agent or editor snap to attention and salivate. Ghost-written books or deals with book packagers--sure, go ahead and list them. Anthologies are okay. Self-pubbed books? Go ahead and list them, but include some sales figures that are likely to impress. What are impressive sales figures for self-published books or story collections? Low end would be around 3,500 copies and upwards. Five thousand copies seems to be a normally accepted bell-ringer.
I usually list my publishing history at the end of my introductory letter. In fact, I always list it. Although my credit list is not large or very prestigious, it does give the publisher an idea, chronologically, what I've done in the past and what my recent sales indicate. I'll show my list and the different categories that I include below, just as an example. I've never been ridiculed for its formatting or subject list. It's always worked for me.
Auto Repair Shams and Scams (Forward--Ralph Nader), 1990, Price Stern & Sloan, Los Angeles--226 pages, non-fiction, consumer warning and repair book.
Garage Sale Mania, 1988, Betterway Publications, Crozet, Virginia--190 pages, non-fiction—1988.
Word Wars, a SF novel, to Rain Publishing, Canada—May, 2007.
Once Upon a Goddess, a Fantasy novel, to Rain Publishing, Canada—January, 2008
Planet Janitor—Custodian of the Stars, a SF novel sold to Engage Books, May 2009
Gate Walker, a Paranormal Fantasy, sold Lyrical Press—January, 2009.
The Lupus Strain, a fantasy thriller sold to LBF Books, February 2009
Stellar by Starlight, to Amazing Stories, 1988.
The Lonely Astronaut, to Amazing Stories, 1988.
Temperamental Circuits, to Gordon Linzner of Space & Time, 1989.
Things that go Clump in the Night, to Richard Fawcett of Doppelganger, 1989.
Dance the Macabre and Dance it Well, to Erskine Carter of Ouroborous, 1989.
Future School, to Chris Bartholomew of Static Movement, January 2006.
The Incredible Mr. Dandy, to Not One of Us.
Planet Janitor The Moon is not Enough, to Enage Books, 2012
Other magazine appearances from 1988 to 1991 include, Alpha Adventures, Small Press Writers and Artists Organization and Sycophant.
The Summit, 15-minute horror play to Night Sounds, Embassy Cassette Inc, Santa Ana, California—1990
Night of the Moa, 13-minute horror play to Night Sounds, Embassy Cassette Inc, Santa Ana, California—1990.
Finalist in the L. Ron Hubbard Writers of the Future Contest, for Temperamental Circuits, 1987.
JOURNALISM AND ARTICLES
350 newspaper profiles, stories, and interviews to Sunset Publishing, Anaheim, California, appearing in The West Coast Jewish News, The Senior Citizens Reporter, and The Military Review. From 1988 to 1991. I have sold three automotive articles to Dollar Stretcher Magazine, from 12-2-2011 to 2-28-2012.
CONTENT AND CLIENT
I have written and published over 1,500 non-fiction automotive, aircraft and marine articles for Demand Media Studios, under the Beta-Automotive and E-How stations, as well as other content and client assignment sites.
Served as content editor of Sunset Publication (see above) for three years. Responsible for all writing assignment content, filler and artwork, formatting and structural editing.
President and founder of Heartland Writers Group, Huntington Beach, California, from 1987 to 1991.
Past agent--XXXXXXXX, from 1988 to 1991.
Past agent—XXXXXXXX, from 2005 to August 2009
CURRENT FINISHED BOOKS (AVAILABLE):
Diane Nine and the Fusion Machine, a military espionage thriller.
Valley of the Mastodons, a non-fiction book involving the Ice Age megafauna discoveries in Hemet, California, during the Diamond Valley reservoir dig. Proposal, chapter outline, and 100 pages available upon request
Dispossessed Incorporated, an urban ghost fantasy.
The Omega Wars—SF, apocalyptic alien invasion (Sequel to PJ)
Screamcatcher, A YA fantasy
The Girl They Sold to the Moon, A YA distopian/SF set in the near future.
This is actually a pretty basic list, which covers a lot of ground. But here's a real good tip that many writers are unaware of: look at the last section where you see CURRENT FINISHED BOOKS (AVAILABLE). These are very brief descriptions of finished, polished novels that I've had in my inventory. What surprised me the most, was finding that agents and editors who read and rejected the initial submission and actually asked to see one or a few of the books on my AVAILABLE list. On one occasion, this lead to a direct sale. On two other occasions, I received referrals, one to another agent and one to a publishing house. So if you have completed manuscripts (not partials), list them at the tail end of your publishing history. And it's kind of important to place your publishing history and bio in the body of the email--not as an attachment, unless otherwise specified.
Planet Janitor: The Moon is not Enough (Engage Science Fiction) (Digital Short) by Chris Stevenson (Kindle Edition - Feb 7, 2012) - Kindle eBook