Nora Roberts is one of the most prolific and bestselling authors in the US.  One of the secrets to her success are her series, both limited and ongoing.  As one of the authors of  The Official Nora Roberts Companion (Berkley - edited by Denise Little and Laura Hayden), I'm please to include information on her various series including the J.D. Robb books for the eBay audience.

• "In The Garden" Trilogy:
• Blue Dahlia (2004)
• Black Rose (2005)
• Red Lily (2005)
• "Key" Trilogy
• Key of Light (2003)
• Key of Knowledge (2003)
• Key of Valor (2004)
• "Three Sisters" Trilogy
• Dance Upon the Air (2001)
• Heaven and Earth (2001)
• Face the Fire (2002)
• "The Irish Trilogy"
• Jewels of the Sun(1999)
• Tears of the Moon (2000)
• Heart of the Sea(2000)
• "Chesapeake Bay" series (originally a trilogy, expanded to 4 books with Seth's story)
• Sea Swept (1998)
• Rising Tides (1998)
• Inner Harbor, (1999)
• Chesapeake Blue (2003)
• "Dream" Trilogy
• Daring to Dream (1996)
• Holding the Dream (1997)
• Finding the Dream (1997)
• "The Stars of Mithra"
• Hidden Star ( 1997)
• Captive Star (1997)
• Secret Star ( 1998)
• "The Concannon Sisters" or "Born In" series
• Born in Fire (1994)
• Born in Ice (1995)
• Born in Shame (1996)
• "The MacKade Brothers"
• The Return of Rafe MacKade (1995)
• The Pride of Jared MacKade (1995)
• The Heart of Devin MacKade (1996)
• The Fall of Shane MacKade (1996)
• "The MacGregors"
• Playing the Odds (1985)
• Tempting Fate (1985)
• All the Possibilities (1985)
• One Man's Art (1985)
• For Now, Forever (1987)
• Rebellion (1988)
• In From the Cold (1990) (novella)
• The MacGregor Brides (1997)
• The Winning Hand (1998)
• The MacGregor Grooms (1998)
• The Perfect Neighbor (1999) 
• "The Stanislaskis"
• Taming Natasha (1990)
• Luring a Lady (1991)
• Falling for Rachel (1993)
• Convincing Alex (1994)
• Waiting for Nick (1997)
• Considering Kate (2001) 
• "Night Tales"
• Night Shift (1991)
• Night Shadow (1991)
• Nightshade (1993)
• Night Smoke (1994)
• Night Shield (2000)
• "The Donovan Legacy"
• Captivated (1992)
• Entranced (1992)
• Charmed (1992)
• Enchanted (1999)
• "The Calhoun Women"
• Courting Catherine (1991)
• A Man for Amanda (1991)
• For the Love of Lilah (1991)
• Suzanne's Surrender, (1991)
• Megan's Mate (1996)
• "Time and Again"
• Time Was (1989)
• Times Change (1990)
• "Loving Jack"
• Loving Jack (1989)
• Best Laid Plans (1989)
• Lawless (1989)
• "Great Chefs"
• Summer Desserts (1985)
• Lessons Learned (1986)
• "Celebrity Magazine"
• One Summer (1986)
• Second Nature (1986)
• "Reflections and Dreams"
• Reflections (1983)
• Dance of Dreams (1983)
• "The O'Hurleys"
• The Last Honest Woman (1988)
• Dance to the Piper (1988)
• Skin Deep (1999)
• Without A Trace (1990)
• "Sacred Sins"
• Sacred Sins (1987)
• Brazen Virtue (1988)
• "Cordina's Royal Family"
• Affaire Royale (1986)
• Command Performance (1987)
• The Playboy Prince (1987)
• Cordina's Crown Jewel (2002)
• "Irish Hearts"
• Irish Thoroughbred (1981) (her first book)
• Irish Rose (1988)
• Irish Rebel (2000)
• WRITING AS J.D. ROBB
• Naked in Death (1995)
• Glory in Death (1995)
• Immortal in Death (1996)
• Rapture in Death (1996)
• Ceremony in Death (1997)
• Vengeance in Death (1997)
• Holiday in Death (1999)
• "Midnight in Death" novella in Silent Night (1998)
• Conspiracy in Death (1999)
• Loyalty in Death (1999)
• Witness in Death (2000)
• Judgement in Death (2000)
• Betrayal in Death (2001)
• "Interlude in Death" novella in Out of this World
• Seduction in Death (2001)
• Reunion in Death (2002)
• Purity in Death (2002)
• Portrait in Death (2003)
• Imitation in Death (2003)
• Remember When (with Nora Roberts) (2003)
• Divided in Death (2004)
• Visions in Death (2004)
• Survivor in Death (2005)
• Origin in Death (2005)
• Memory In Death (2006)
• “Haunted in Death” novella in Bump in the Night (coming April 2006)
• Born In Death (coming July 2006)