Various tools for writers operated by the ReAnimus Press crew:

SF in Dimension, by Alexei and Cory Panshin
Anthopology 101: Reflections, Inspections and Dissections of SF Anthologies, by Bud Webster

General:

Specific to Smashwords:

Modern Science Fiction, by Reginald Bretnor, ed.
The Science Fiction Novel, by Basil Davenport, Robert A. Heinlein, C. M. Kornbluth, Alfred Bester, and Robert Bloch
Galaxy Magazine: The Dark and the Light Years, by David L. RosheimHaving Relationships With Characters on the Road to Great Fiction, by Andrew BurtHow To Improve Your Speculative Fiction Openings, by Robert QualkinbushIn Search of Wonder, by Damon KnightFootprints on Sand, by L. Sprague de Camp and Catherine Crook de CampThe Issue at Hand, by James Blish (as William Atheling, Jr.)Space Travel - A Science Fiction WriterThe Craft of Writing Science Fiction that Sells, by Ben BovaStaying Alive - A WriterHeinlein in Dimension, by Alexei PanshinOf Worlds Beyond, by Lloyd Arthur Eshbach, ed.Heinlein