Strictly the ones that gave me inspiration

• Ray Bradbury: Zen in the art of writing
• Orson Scott Card: Characters and viewpoint
• Keith Johnstone: Impro for storytellers (this is about acting rather than writing, but useful for writers too)
• Stephen King: On writing
• Holly Lisle: Writing fiction for love and money
• Paul Matthews: Sing me the creation
• John Clark Pratt: Writing from scratch: The essay
• Jerome Stern: Making shapely fiction