As well as the novelization, there will also be a streight forward comic adaptation, and several Green Lantern movie related prequels in the comics -
http://dcu.blog.dccomics.com/2011/02/10/green-lantern-prequels-to-be-published-this-may/
Written by the creative talents behind the highly anticipated motion picture, these exclusive one-shots tell the tales of the movie characters before the events of the film. What were Hal Jordan, Sinestro, Kilowog, Abin Sur and The Guardians all doing before the curtains rise on June 17?
Experience it all in these one-shots, as told by the superstar Green Lantern movie team including producer Geoff Johns (GREEN LANTERN, THE FLASH), screenwriter Michael Goldenberg, producer/screenwriter Greg Berlanti, producer Donald De Line, screenwriter Michael Green (SUPERMAN/BATMAN) and screenwriter Marc Guggenheim (JUSTICE SOCIETY OF AMERICA). Each issue will be available day-and-date digitally for $2.99.
GREEN LANTERN PREQUEL SPECIAL: SINESTRO #1
Written by GEOFF JOHNS and MICHAEL GOLDENBERG
Art by FERNANDO DAGNINO
Movie art cover
GREEN LANTERN PREQUEL SPECIAL: KILOWOG #1
Written by PETER J. TOMASI and ADAM SCHLAGMAN
Art by JOE BENNETT and FABRIZIO FIORENTINO
Movie art cover
GREEN LANTERN PREQUEL SPECIAL: ABIN SUR #1
Written by MICHAEL GREEN
Art by KARL KERSCHL
Movie art cover
GREEN LANTERN PREQUEL SPECIAL: TOMAR-RE #1
Written by MARC GUGGENHEIM
Art by CLIFF RICHARDS
Movie art cover
GREEN LANTERN PREQUEL SPECIAL: HAL JORDAN #1
Written by GEOFF JOHNS, GREG BERLANTI and DONALD DE LINE
Art by JERRY ORDWAY
Movie art cover