Check out this article that appeared in the Summer 2004 issue of The
Scarlett Letter, newsletter of the Southeast Chapter, Mystery Writers of
America:Promotion Is Key to Selling Books by Chester D. Campbell
Here's an article that will show you, step-by-step, how to produce an
attractive, low-cost folder for use in promoting your books:
Promotional Folder and How to Do It by Chester D. Campbell
Check out this modernized version of S.S. Van Dine's celebrated rules for
detective story writing:
Twenty rules for writing a detective novel
by Rina Brundu Eustace