Book excerpt: Perhaps the best-kept secret in the publishing industry is that many publishers--both periodical publishers and book publishers--make available writer's guidelines to assist would-be contributors. Written by the staff at each publishing house, these guidelines help writers target their submissions to the exact needs of the individual publisher. ""The American Directory of Writer's Guidelines"" is a compilation of the actual writer's guidelines for more than 1,700 publishers. A one-of-a-kind source to browse for article, short story, poetry and book ideas.