Various tools for writers operated by the ReAnimus Press crew:

Modern Science Fiction, by Reginald Bretnor, ed.
Anthopology 101: Reflections, Inspections and Dissections of SF Anthologies, by Bud Webster

General:

Specific to Smashwords:

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