Core "Dragonlance" Series:
* The Chronicles Trilogy: Dragons of Autumn Twilight, Dragons of Winter Night, Dragons of Spring Dawning (3 books)
* The Legends Trilogy: Dragons of Summer Flame, Dragons of a Fallen Sun, Dragons of a Lost Star (3 books)
* The War of the Lance Trilogy: Dragons of the Red Sun, Dragons of the Red Moon, Dragons of the Red Star (3 books)
* The War of the Twins: The Soulforge, The Dawning of a New Age, The Dragons of a New Age (3 books)
That adds up to 12 core books, making up the "classic" Dragonlance.
Other Dragonlance Fiction:
* The "Legacy of the Lance" series: A series of 5 books that continue the stories of the classic trilogy.
* The "Dragonlance Adventures" series: A series of 10 books with more standalone stories.
* The "Dragonlance Heroes" series: A series of 9 books focused on individual characters from the series.
* Other books: There are also a number of standalone books and short story collections.
Adding all those in, the Dragonlance series contains well over 40 books.
Note: Some Dragonlance books are also available as boxed sets or collected editions.
It's important to keep in mind that the Dragonlance series has undergone a number of revisions and reprints over the years. Some books have been updated or re-written, and there are various different editions available.