Various tools for writers operated by the ReAnimus Press crew:

The Science Fiction Novel, by Basil Davenport, Robert A. Heinlein, C. M. Kornbluth, Alfred Bester, and Robert Bloch
Space Travel - A Science Fiction Writer

General:

Specific to Smashwords:

Modern Science Fiction, by Reginald Bretnor, ed.
How To Improve Your Speculative Fiction Openings, by Robert Qualkinbush
Galaxy Magazine: The Dark and the Light Years, by David L. RosheimIn Search of Wonder, by Damon KnightOf Worlds Beyond, by Lloyd Arthur Eshbach, ed.Footprints on Sand, by L. Sprague de Camp and Catherine Crook de CampHeinlein in Dimension, by Alexei PanshinThe Craft of Writing Science Fiction that Sells, by Ben BovaThe Issue at Hand, by James Blish (as William Atheling, Jr.)Anthopology 101: Reflections, Inspections and Dissections of SF Anthologies, by Bud WebsterSF in Dimension, by Alexei and Cory PanshinHaving Relationships With Characters on the Road to Great Fiction, by Andrew BurtStaying Alive - A WriterHeinlein