Assuming you're talking about the entire saga:
This has been going on for a couple of years now, across two and sometimes three books.
You're never going to get a single book. Maybe a collection of omnibus' but they'll be prohibitively expensive. You're better off getting the graphic novels.
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Green Lantern: Rebirth (collects the six issue miniseries) (Mar 28, 2007)
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Green Lantern VOL1: No Fear (collects #1-6) (May 20, 2008)
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Green Lantern Corps: Recharge (five issue miniseries) (Jun 21, 2006)
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Green Lantern VOL2: Revenge of the Green Lanterns (#7-13) (Oct 7, 2008)
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Green Lantern Corps VOL1: To Be a Lantern (#1-5) (May 2, 2007)
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Green Lantern VOL 3: Hal Jordan - Wanted (#14-20) (January 13, 2009)
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Green Lantern Corps: The Dark Side of Green (#7-14) (November 7, 2007)
Ion Vol 1
Ion Vol 2
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Sinestro Corps War, Vol. 1 (GL #21-23 and GLC #14-15) (May 5, 2009)
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Sinestro Corps War, Vol. 2 (GL #24-25 and GLC #16-19) released on June 23, 2009
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Tales of the Sinestro Corps (various one-shots and backstories of the Sinestro Corps) released on June 30, 2009
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Green Lantern Corps: Ringquest (#19-20, 23-26) (December 2, 2008)
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Green Lantern: Secret Origin (#29-35) (December 16, 2008)
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Green Lantern: Rage of the Red Lanterns (#26-28, 36-38, and the FC one-shot) released on July 7, 2009
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Green Lantern Corps: Sins of the Star Sapphire (#27-32) released on June 9, 2009
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Green Lantern: Agent Orange (#39 - 42) released on November 10, 2009
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Green Lantern Corps: Emerald Eclipse (#33 - 36) released on November 10, 2009.
That catches you up to Blackest Night at least.