Margaret Weis is, in my opinon, a great fantasy/sci-fi author. She has written numerous books and co-authored with many authors(often with Tracy Hickman) in many of her books. One of the series she and Hickman wrote which had sparked many other books by other authors are the Dragonlance Chronicles. The trilogy that they wrote had given way to dozens of other authors writing prequels, sequels and short anthologies about it.

Dragonlance Chronicles(co-authored with Tracy Hickman:
Dragons of Autumn Twilight
Dragons of Winter Night
Dragons of Spring Dawning
Dragons of Summer Flame(This was written many years after the three books above.)
My page on Dragonlance

Dragonlance Legends(co-authored with Tracy Hickman):
Time of the Twins
War of the Twins
Test of the Twins

Star of The Guardians:
The Lost King
King's Test
King's Sacrifice
Ghost Legion

Darksword Trilogy(with T.H.):
Forging the Darksword
Doom of the Darksword
Triumph of the Darksword
I didn't like this series at all.

Rose of the Prophet Trilogy(with T.H.):
The Will of the Wandereer
The Paladin of the Night
The Prophet of Akhrin

The Death Gate Trilogy(with T.H.):
Dragon Wing
Elven Star
Fire Sea
Serpent Mage
The Hand of Chaos
Into the Labyrinth
The Seventh Gate
I didn't read this series yet so I'll appreciate any info you send in about it :)