In reading order
Kobold Guide to Roleplaying
Gail Simone
Kobold Guide to Worldbuilding
Jeff Grubb, Michael A. Stackpole
Kobold Guide to Board Game Design
Richard Garfield, Mike Selinker, Richard C. Levy, Rob Daviau
Kobold Guide to Plots & Campaigns
Margaret Weis, Wolfgang Baur, David Zeb Cook, Jeff Grubb, Robert J. Schwalb, Richard Pett
Kobold Guide to Gamemastering
David Zeb Cook, Monica Valentinelli
Kobold Guide to Magic
Martha Wells, Wolfgang Baur, Jeff Grubb, Ed Greenwood, Monte Cook
Kobold Guide to Dungeons
John Joseph Adams, Wolfgang Baur, David Zeb Cook, Keith Ammann, Keith Baker, Lawrence Schick, Sadie Lowry
Authors
David Zeb Cook Ed Greenwood Gail Simone Jeff Grubb John Joseph Adams Keith Ammann Keith Baker Lawrence Schick Margaret Weis Martha Wells Michael A. Stackpole Mike Selinker Monica Valentinelli Monte Cook Richard C. Levy Richard Garfield Richard Pett Rob Daviau Robert J. Schwalb Sadie Lowry Wolfgang Baur