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:

Heinlein
The Issue at Hand, by James Blish (as William Atheling, Jr.)
Having Relationships With Characters on the Road to Great Fiction, by Andrew BurtHow To Improve Your Speculative Fiction Openings, by Robert QualkinbushHeinlein in Dimension, by Alexei PanshinIn Search of Wonder, by Damon KnightThe Craft of Writing Science Fiction that Sells, by Ben BovaFootprints on Sand, by L. Sprague de Camp and Catherine Crook de CampModern Science Fiction, by Reginald Bretnor, ed.Galaxy Magazine: The Dark and the Light Years, by David L. RosheimMore Issues at Hand, by James Blish (as William Atheling, Jr.)Space Travel - A Science Fiction WriterStaying Alive - A WriterOf Worlds Beyond, by Lloyd Arthur Eshbach, ed.