Cosmere timeline

Brandon Sanderson's Cosmere is planned to be a massive literary undertaking, with around 40 books planned by the time Sanderson is done. There are around 12 full books so far, a compilation book containing most of his short-stories and novellas, and a graphic-novel trilogy.
 * MistBorn Era 1 (3): The Final-Empire, The Well of Ascension, and The Hero of Ages
 * MistBorn Era 2/Wax and Wayne (3 so far/1 more): The Alloy of Law, Shadows of Self, The Bands of Mourning, and The Lost Metal (not published yet)
 * StormLight Archive: The Way of Kings, Words of Radiance, OathBringer, Rhythm of War
 * Standalone books (Sanderson intends to publish sequels): Elantris and WarBreaker
 * White-Sand graphic-novel trilogy

=Ancient history of the Cosmere= Events taking place over ten-thousand years before any of the Cosmere books that have been published so far.

Yolen
=Classical history of the Cosmere= Events taking place long after the Shattering of Adolnasium but over a millennium before any of the Cosmere books that have ben published so far.

Scadrial (classical)

 * Preservation (Leras) and Ruin (Ati) come to the Scadrian system and use their combined power to create the planet Scadrial
 * Unknown period of time after the Shattering but presumably several millennia before the rise of the Final-Empire

=Recent history of the Cosmere= Events taking place within the last five-hundred years of the Cosmere books that have been published so far.

Nalthis (recent)

 * The ManyWar: a massive world-war on Nalthis
 * Happened some three-hundred years before the events of WarBreaker
 * Similar time-period: between the closing years of the Final-Empire and the first decades after the Catacandre (Final-Ascension)

Scadrial (recent)

 * Book series: MistBorn Era 1

Sel

 * Book: Elantris

Taldain

 * Book series: White-Sand graphic-novels

=Current events of the Cosmere= Events taking within about a decade of the latest published Cosmere books.

Nalthis (current)

 * Book: WarBreaker

Roshar (current)

 * Book series: StormLight Archive 1-4

Scadrial (current)

 * Book series: MistBorn Era 2/Wax and Wayne

=Near-future of the Cosmere= Events that will take place within the next century or so in Cosmere books that are soon to be published.

Scadrial (near-future)

 * Book series: MistBorn Era 3 (set to be published from 2025-2027)

=Future Space-Age of the Cosmere= Events that will take place within the Space-Age of the Cosmere, probably many centuries down the line from the current Cosmere books, where futuristic space-travel is possible and the universe takes on a more sci-fi quality

Scadrial (Space-Age)

 * Book series: MistBorn Era 4 (likely to be published sometime around or after 2030)